I have no idea what the numbers inside the shoes stand for, but as of the three numbers you mentioned the only one that I am familiar with is 363, I expect it to be the last your shoes are on.
It's a pair of Peal & Co nubucks I picked up from BB's recent 70% off sale. It's definitely C&J from the heel pattern but I don't see the shoes on C&J's website so I turned to you guys.
Any thoughts on trees for the 363 last? The trees I have are all from BB and Woodlore, which are made by AE and are bulky. Would these trees damage the shoes by stretching it too much? Are there cheaper alternatives to the standard C&J trees (I'm seeing $100) that are slim and fit well into the 363 last?