LOL why did I know it was a model 12.
Yes sir must be why the 870 put your model 12 out of production
I have one 42 and a two model 12's ( 16ga & 28ga ) left in my herd also but only because of what current value these particular gauges have plus they were my grandfathers and I am no spring chicken . They are a gun of the past and the EE here shows that the last number of years as values continue to drop and drop
By the way who fixes model 12's now when somethings goes wrong, how about even getting the sleeve adjusted or why the firing pin protrudes.

Try asking that one with a gunsmith today and watch the blank look

I will not even mention what some call timing
The old 870 like it or not lives on since introduced in 1950 and will keep banging shells with new owners long after we are dead and all the model 12's are rebar .
870 parts are everywhere. Easy to work on etc not so on the model 12
Cheers