I find that Model 21's are not only excellent clay and field guns but are an outstanding tangible asset. I consider them money in the bank.
I've never been one to go for the 12 gauge PG F/M but search out interesting sub gauge Skeet guns.
Either that or English stocks, double triggers or looooong barrels.

They make excellent trading fodder as most everyone I do business with recognizes the value of the brand. Never a penny lost.
I pity you Mr. M for having passed down dozens of these fine shotguns.
I'm a little blue myself as I just traded away 4 of mine for a soon to be Galazan Fox.