I'm no expert on Model 41's, but I'll try and help out. Both my examples are from 1981, so not too far off from the one you are considering.
The general consensus is that the older pistols, up to at least the late '80s and some say into the early '90s are superior in materials, workmanship, and finish. There are some anecdotal exceptions, thus the "general consensus" comment.
If you are buying it in person, like from an individual or LGS, make sure you visually inspect every part of the pistol, preferably disassembled. Look for areas of excessive wear from a steady diet of high velocity rounds. Standard velocity only should be shot in a Model 41.
If you are buying it online, make sure there is an agreed upon inspection period. If you know a good gunsmith, take it to him and spend a little money to save a little money.
Newer magazines are hit and miss. Look for older magazines with a metal follower, or at least the lazy ampersand versions.
Model 41's are a pleasure to shoot, and if used with std. velocity ammo, cleaned fairly regularly, and properly cared for, will end up going to your children and their children.
That's my 2 cents. I'm probably missing a lot, but hopefully I haven't given you any wrong info. I'm hoping the real experts will be along to expound on my musings.
Here are my two 41's
