First Drew, there are no "stupid newbie" questions here, so don't put yourself down. Getting the right thread is always a problem. I use vintage 100% cotton thread bought off eBay. Despite some research, I have yet to figure out the size/weight labels on thread spools. Any modern thread of suitable thickness is going to have polyester or some other synthetic in it to give strength so I can't use that on other people's helmets. As this is your piece, you can decide....modern VS vintage. The vintage thread I use is Dorcas 2oz. 12 cord machine thread #40. I also have a #35 from the same company which is slightly thinner. The colour used is black. Another alternative to use is "Binder's Thread", unbleached linen made by Lineco Inc. MA, USA again available on the net. This is specially made for those who rebind books by hand. You would have to dye it black but it is a natural thread and won't "light up". The item # is 402-0050. It takes about 1.5 M or 40" of thread to stitch a visor. You may have some left over when you finish but it is far better to have that then run out of thread in the middle of the visor. I am sure there would also be UK companies that make this. I have not had good luck with vintage linen thread as it quickly frays and breaks when used on leather for some reason. This binder's thread however, does work.
Regarding needles, I don't use blunt ones, you can use any sewing needle bought in those multiple packs. The important things is that the "eye of the needle" is large enough for the thick thread you are going to be using. If you want to get more specialized, I can recommend glovers needles made by John James ........sizes 3/7 #JJ18037. These are made in the UK and it is a 3 pack with 3 different size needles specifically designed for leather. I find that I use their #3 needle the most. Again you can order these on the internet.
Last, just a quick repeat of what I have listed in previous posts TOOLS: pin vise drill and bits, bee's wax, curved needle nose pliers, rubber finger tip and T pins. The rubber finger tip goes on the middle finger and allows you to really grip the needle and protects when you are pushing it through the stitch holes. Even so, you will probably shed some blood
while doing this! WAX your thread before and during the restitch!!
Regarding your visor trim...I have no doubt that both it and the spine were taken off this helmet. In 3 decades of doing this I have only had one piece of replacement trim that fit perfectly with the holes matched up. That happened this year! Feel free to ask any further questions Drew.
He has a few ebay-names on ebay.fr.
