What you have is a 1S Sporter, not a 1H Tropical. I also have a 45-70 1S in the 130-02XXX range, and according people more knowledgeable than me, it was produced at the same time as the non-prefix 45-70s. It has all the non-prefix attributes except the early forearm checkering pattern (Ruger apparently put only the later forearms on anything that had a SN prefix - or at least that's been my experience).
The 1H 45-70 is a very rare bird and commands very high prices in collector circles. I've seen estimates of 12-20 having been produced and to my knowledge, these were all made in 1976 and have the "200year" stamp on the barrel. Speaking of barrels, the 1H 45-70 will have a heavy (D weight) 24" barrel, while the much more numerous 1S will have a 22" Sporter (B weight) barrel.
FWIW, the recently produced Lipsey special runs in 45-70 have a 26" C-weight barrel, same as the 1V and the 375 H&H 1H. This is the 45-70 I had waited for for years and quickly picked one up as it's the perfect mix of weight, length, balance, etc. for this round.