I also have an H&R .410 in 2,5 chambering Topper that I got for Christmas in 1959 when I was 8. Many a squirrel and bunny fell to this piece. The surprising thing is how well it shoots rifled slugs (not for deer). Still use it for back yard trap shooting.
I was given my father in laws Japanese Arisaka that he brought back from WW ll. He used it for deer hunting. I believe it came in two calibers. I have no interest in firing it. I keep trying to give it to my sister in law because I feel one of her sons should have it.
As far as what I have...