Spend 30 seconds with an angle grinder, and the concern about that stamped number will be a moot point to at least 90% of stovebolters, probably more like 99%. Getting one's knickers in a twist over numbers seems to be a pretty fruitless pursuit. Replacement blocks weren't stamped, and they work just as well as "numbers-correct" ones.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!