It seems as though it is always the weird things that take the most time to hunt out. This time I am searching for alternatives for fake rivets. I believe the last time I did this the rivets were on the smallish size, and I think we made them by sculpting them around a bolt head. They looked nice, but were time consuming if I remember correctly.
One option I am looking at is upholstery tacks. The size I am looking for current is around an 1 1/2" and there are a few that come close, and look good. DIY Upholstery Supply has a number of decorative nail options larger than an 1". Such as:
The other option is mushroom plugs or buttons. I can get these in hardwoods that will match the rest of the construction, but do not come in the current size I am looking for. While these are pretty common, Bear Woods has a variety of wood parts and pieces. They also have a variety of wooden game parts. Cherry Tree Toys has a similar stock of merchandise, which I have used before.