As a collector, I would prefer that people not add more stickers. I’m ok with existing ones that were contemporary to the time as it reflects the typewriter’s era.

If you are using the machine in a working capacity and need a label for asset tracking, by all means. But for machines in my collection, I’m happy having the serial number in a spreadsheet.

I think I would lean towards a card that goes along with the machine that includes information and ownership history.