Model 42/24?

Hey guys. I hope all is well with you and I apologize for what probably a very simple question.
A firing pin broke on, what I believe to be my model: 42; 22/410 over and under. It is black, with red trim. Nice gun-I really do, or did, enjoy shooting it. I have not had it for 2-years. I dropped it off at a gunsmith who had it for a year and every time I dropped by it was always something-he was sick, busy with wealthier clients-I mean putting together expensive rifles (code for I just bought a C&C machine), aliens landed and spirited him away...part deux, dropped off at second smith who told me he could fix it. They both corrected me that I had a model 24 (serial number ends in: 7167; I,ve had the weapon new for just over two years-pin broke plinking one season.).
I called Savage and was told it was a 42 and the store where I made the purchase ordered me the replacement part-had it in a week-THANK YOU SAVAGE!!
Now, I take it to the second smith who tells me they will not work as they are for a model 42 and that I have a 24. FACE PALM...
I told him to try anyway and that I was in the store when the owner called Savage-they were given the S/N and date of purchase and was told it was a model 42, not a 24.
So the smith, with an "Ill please the customer and look at the part anyway look" pulls the pin out of the envelope his poker face left him. He told me he'd get to it.
So, again, do I have a 24 or 42?
It is the ubiquitous black 22/410 over under with red trim just over 3-years old. Every 24 I have been able to find are made of wood. Any help would be appreciated. I hope, when I call in a week it will be done. My fiest thinks I hate him, now-he hasn't been out in a while.
Thanks for your help