They didn't call them 1899A, 99B, 99C, 99D, etc. The 18 was gone from the model designation. All models were 99's!
Technically not absolutely true. From 1920 thru 1923 or so there was a mishmash of 99 and 1899 nomenclature used in ads, and I had a 1922 price list which listed all the models as 1899's (1899A, 1899B, 1899C, 1899D, etc).
It would be simpler if it was true that they stopped using 1899, but it's not true. Nothing about Savage is easy. This is why I quit fretting about whether something was a late 1899 or an early 99 several years ago.
Did I hit a home run? David
We'll call it a triple.