Its been years since I picked up my box ,it last a really long time. Maybe a good paint store I was thinking I got mine at a hardware store. Just use an old tee-shirt and dip in veg oil then in the pomice powder rub the bow all over keep dipping to keep the shirt wet. Wipe down with warm water then dry good. May take a couple of wipe downs but it takes off shine but leaves the finish perfect. I use it to take shine off all my hunting selfbows.
I did a search and I believe you can get it at like Home depot or Lowes.
Just to let you know I got this method years ago from BB I, it should go well with your great find of a bow. I am jealous.