The date code can be 2 or 3 characters - 1 or 2 numbers followed by a letter. That serial number should date to 1953, so your stamp was probably 20E and the E just wasn't struck heavily enough.
And if it has a schnable tip on the forearm it will be a 99EG, if it has a fat and wide forearm with rounded end then it will be a model 99R.
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“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