Yes, you could make them. All you need the type of saw that cuts out circles and some metal washers and screws. But, when I needed the large ones it cost me 8.58 GBP for a whole packet of them (10?) including postage to Australia. hardly worthwhile messing around with. I would assume the little ones would be much cheaper.
I would let Simon know without expecting any compensation, just hoping he may have a little chat with his body makers and in the future they will make better bodies.
i got to the point that I only buy kits from people who have bodies made really well; like Gudrun Legler; her kits come with beautiful perfectly fitting bodies when purchased directly from her. Sadly, some of her suppliers advertise them as having “custom made bodies for each kit” and they are nothing of the sort. I got one with the arm cap hole twice as big as the top of the arms. I sent it back, made my own body, and will never buy from that supplier again.
This is how I make my bodies, when I have to
Notice that I place the joint more over the seam on the top of the cap; especially on the limbs