You can use a hole cutter & make your own plugs.
https://www.midwayusa.com/product/1748143360
You can also buy the Winchester Repoduction pad & they come with small plugs & grind off the logo. Galazon use to have these in 2-sizes: large & small. They did a close out on the small, but if you call they may still have some in stock. The small size were perfect for the small gauge stocks