Product serial numbers and information on older scope accessories (i.e. 453A)

I have a 453A oscilloscope rack mount. In working condition. Wondering if there is a place to find a serial number and get more information on this unit.

The best place is this customer's website: https://w140.com/tekwiki/wiki/453

Another one would be VintageTEK:
https://vintagetek.org/

Serial number location could be right under the 543A-4 on front.
Or lower left by Channel one on the 453A-1.
Sorry, not sure for the Rackmount verison.
Very old scopes liek this were usually on the front.
1980's and up were on the back.