ATEA. MODEL 50 Date coding question

[RotoTech99]

Dear Forum:

Hello, I have an ATEA Model 50 that I've completed some conversion work on that I need some information about some codes I found on it, please.

The first code is 1954 in a rectangle on the capacitor bracket, then CK-3 on the internal plate.

Can someone in the Forum familiar with ATEA & BTMC sets please assist with translating these codes?

Thank You,
RotoTech99