$600 was a lot of money in 1960. Wasn't a nice S&W in the $80s back then? That would be about $600 today, right? (quick head calculation).
I cited $600 'cause that's a pretty common price, nowadays. I think S&W went for more than $80, new, back in the 60's -- but it's hard to find original prices to be sure. Used, maybe...
Let's look at some easier ones:
1) One I had, and now regret selling: a S&W 547 MP in 9mm. Original price was $317, they sell for $775 NIB, and were discontinued in 1985. Keeping even with inflation required a sale price of $675... which is what one in 98% would bring. Only a NIB model would be a true investment, and offer only a $160 gain for having been invested for 27 years -- that's an annualized return of 3.4%. A little better than a savings account, nowadays, but not back during some of that period.
2) A standard Model 25 made in 1991, sold for $429, but would have to sell for $926 to just stay even in buying power. The Blue Book says today's price, in NIB condition, is $550. I've seen them for a bit more, and a bit less -- but never in 100% condition.
Most of the very nice S&W revolvers i've seen seldom sell for more than $550, regardless when they were made -- and darned few of them are in the condition a collector would want for a gun considered as an investment.
3) There
are exceptions, like a .45 LC version of the 25 (1955 Target Model). It sold for $347 new, was discontinued in 1985, and now sells for $4,200 in NIB condition. Inflation-adjusted value for that original investment would be $740, so that one would be a winner.
Guns, generally, aren't good investments. They are expenses. Like cars. That doesn't mean you shouldn't buy them or collect them, but it does mean you really have to buy and collect wisely if you really hope to make money on the effort.
(I'm a gun nut, like many here -- but I was also a Certified Financial Planner for a number of years, and look at some of these things differently.)