No, 99's from 1952/1953 with steel or case colored rotors are fairly common. Lots and lots of 99's made in those years.

An earlier one with it would be uncommon, but I think we've seen a couple? First, what's the serial number range and what's the stamp on the front of the lever? Should be 1 or 2 numbers followed by a letter in a circular stamp, on the front of the lever boss above the serial number. Like this:

[Linked Image from savagefest.net]

“The Savage 99 Pocket Reference”.
All models and variations of 1895’s, 1899’s and 99’s covered.
Also dates, checkering, engraving.. Find at www.savagelevers.com