You could turn one out of a hardwood, maple easily enough and paint it. There's a guy in Seattle area that produces 3D printed projectiles if you search him. I have three of his.
Yep, the 35mm...I had to make a projee for that one myself because some just won't ever turn up here. I had to do that with a 1.1" US Navy casing yesterday. I have two casings and I'll never find a projectile in Canada while one collector in the US had five or six complete rounds...not fair. Here's my cases followed by what they SHOULD look like.
this one popped on FB Market today , but is a hour and a half away