I think the Hastilow plates also come in a couple different shapes
Am I misunderstanding your intention here, or are you trying to make an adjustment to the headplate do the job the panel is meant to do? Is your horse the typical skid row panel type? Am I misreading, or are you trying to pinch [only the] top of the headplate to accommodate a prominent wither?
I probably wonât do it at all. I and a large group of wide horse owners constantly fight having a U shaped horse in an A shaped world. Luckily for me, I found a used saddle that fits. But it was sure frustrating when I would try a saddle and I could clearly see that if it was just a smidge wider at the top⊠maybe an inch⊠it would be perfect.
I currently own two saddles for my OTTB. His shape changes so much between in work and out of work that a fitter would not be able to reflock to accommodate him, and he suffers from lameness issues so he regularly gets long breaks. So I wonât need to do this. But if I ever stumbled across a cheap adjustable saddle, I may pick it up just to try it. It wouldnât have any sort of warranty anyways.