I have owned several No.2's. My 12b is a late 70's production and my 20b is an early 90's production.
There are night and day differences in the finish. The 90's production is excellent in wood to metal, and metal to metal.
The 70's production is equal in terms of wood to metal, but not in metal to metal. The 70's production isn't nearly as tight where the sidelocks nest in the frame. This isn't associated with wear and tear.
That said, it has still gone bang every time I pulled the triggers, which is probably about a thousand times.
If you get one at the right price, go for it. But I've found that there hasn't been a lot of difference in price between earlier and later No. 2's.
Hope this helps......
