Yes, those holes are uneven.
The round holes go all the way through the billets. The oval holes must have been leftovers from the old, split laminate billets they salvaged to put this pair together!
Whoever made these tried to stitch them together, but missed a rather long stretch, which allowed the billets to ...
... split. Highly unsafe.
Anyway ... They'd been sewn on with what looked like dental floss. The stitching on the middle billet was loose, the tree was alarmingly soft, and the stitching that held the rear of the panels on was broken. I repaired everything, and even with my charges, the customer had a sound and useable saddle for a very good price. Then, a customer returned a used saddle she'd had on trial because it "squeaked" and she was worried about the tree's integrity. (I took it apart. It was fine ... just squeaky.) Third, someone on one of the bulletin boards wanted to know how to tell if the used saddle she was trying had a broken tree. So I guess the Horse Gods and Goddesses are telling me it's time to do an entry about safety checks on saddles.
If you're buying a used saddle from a reputable shop, chances are very good that the shop has already done a safety check. But if you're buying from some other source, that individual might not be knowledgeable enough to determine if there are safety issues with the saddle they're selling (like the person who made the billets pictured above, or the person who once asked me - in all seriousness - if I thought she should sell her saddle because "my horse fell over on his back and rolled on the saddle - I guess he didn't like it, so I'm thinking I should sell it?"). So if you're buying a used saddle (or selling one, particularly given the litigious society in which we live), here's a checklist. Keep in mind that the only way to tell for sure if a saddle has a broken tree or other "internal injuries" is to have a saddler / fitter drop the panels and expose the tree ... but this list can give you an idea if such measures are necessary.
First, eyeball the saddle, either with it sitting on a saddle buck, or with the pommel on the ground and the cantle in hand. Sight down the approximate center of the cantle, and see if everything looks normal from front to back. The following are examples of what you don't want to see:
The yellow dot is the center of the pommel, and the red dot is the center of the cantle. Note that the two don't line up. This saddle tree was twisted from being consistently mounted from the ground. This is an issue that can sometimes be corrected by a saddler ... and sometimes it can't. The tree can be straightened, but whether it will stay straight is anyone's guess.
Again, the center of the pommel is marked in yellow; center of the cantle, in red. The green line shows the misalignment of the saddle nails. The panels are flocked and sewn on unevenly. This saddle was practically brand-new, but was an "economy" model ... and was crooked due to poor manufacture.
This is an extreme example of an old saddle that had always been mounted from the ground. It would make a wonderful piece of decor in the home, or could be used for demonstrating what a crooked saddle looks like ... and that's about it!
Now, keep in mind here that the flocking can be compressed unevenly, but the tree itself should be straight. And do check the flock - it may be hard or lumpy or full of divots; if it is, a strip-flock should be done.
Next, grab the stirrup bars and give them a healthy wiggle. They should not move. If they do, you might want to pass on that saddle.
Do a flex test of the tree next. Prop the pommel on your thigh, grab the cantle, and pull the cantle toward the pommel (putting one hand in the middle of the seat can be helpful):
There should be some give (though some older synthetic trees won't flex at all), but this is a good example of too much flex - see the wrinkles in the seat and the bend? While seat wrinkles don't always indicate a broken tree, being able to almost fold the saddle in half is a dead give-away. Broken tree. Didn't even have to open that one up to figure that out.
Next, "mount" the saddle and clamp your knees against the area of the stirrup bars. Squeeze your knees inward:
The pommel arch should not move at all. If there's any give or funny noises, it could be a broken head plate.
Next, grab the dee rings and make sure they're firmly attached. The dee is attached to what's called the "falldown staple", which is one of the major components responsible for keeping leather and tree together.
Finally, check the billets and the stitching. Grab the panels and give 'em a pull to make sure they're stitched on securely. Inspect the stitching on the flaps / sweat flaps / knee roll/blocks. Make sure the leather safe and sound and not cracking, flaking, torn or worn through anywhere. Make sure the flaps are firmly attached to the tree, and check the billet webbing to make sure it's in good shape.
Again, it's really impossible to tell definitively if a saddle is in good shape without taking it apart, but these tests will tell you if that radical sort of operation is necessary. And while some repairs are pretty easy to do and relatively inexpensive (billets usually run about $25 each, a strip flock is between $250 and $350, and stitching is usually pretty reasonable), the tree is another story. Some saddlers will do tree repairs if they're minor, such as replacing a rivet, but some won't even attempt a tree repair because of safety and liability issues. And while it's possible to re-tree a saddle, it's not cheap - think along the lines of $300 - $500 plus the cost of the tree (which varies greatly depending on the manufacturer, but do expect to drop $200 at the very least). So if the used saddle you're looking at needs some repairs, do your math to make sure that "bargain" really is one!