Stainless case 992B- All I have found so far is that latterly Hamilton sold their watches in a variety of cases, 10K, 14K and stainless steel. No date found so far for introduction of stainless steel.
My 992B has a factory dial, 525 CP* 24 hour Black, in melamine (melamine introduced in 1948 and on all by 1950).
*CP = Canadian Pacific, but the watch was also used by Canadian National and other RRs. in Canada.

My case is model 7, a 10K gold filled made by Fortune of Canada. (Fortune made cases for factory watches, as well as for recasing watches by jewelers).

I did find that a few 992B movements were sold to jewelers for casing to the customer's wishes.

I also found that 525,000 992B watches were made and sold, continuing up to the closure of the factory.
This makes the 992B one of the most popular of all precision watches.

I will keep looking for the date of introduction of the steel case.