I wouldn't trade or sell the old steel framed Marlin.
I believe that the older, North Haven Marlins are going to appreciate considerably.
I'm not really enthralled with the Henry rimfires. Their levers are copies of the Ithaca/Erma Werke pot metal (zamak/mazak) .22's. Zamak does have a nasty habit of sometimes disentegrating after a number of years- the Corgi, Ertl and Lionel collectors have experienced this first hand. I've got a Lionel 262 that needed a new frame because the original just warped and disintegrated. There is no way to tell when it will happen, or if it ever will. Sometimes it can happen in 10 years, sometimes it takes a century.
I've got an Ithaca 66 .410 supersingle with a zamak frame, and it's a good little gun, but it is starting to show signs of subtile corrosion.
If you can find a good used Marlin 39, or one of the Rossi 62's reasonably, I'd recommend one of them- they are steel, and will last a lifetime.
Just my two cents.