I found one such label inside the 401A I resurrected this weekend. It was nice to see "some" information about it. I knew by the label that it worked in 1977 and which shop had cared for it. It was a repair tag, not a service tag,.. assuming they're different.
The only thing that makes me wonder about this is our litigation happy society. If I do an honest repair, then Joe Avg gets it after me, botches something, then something happens, it's my name on the machine, not his.
Quilts, Furniture, etc are not likely to burn your house down or jump stop your pacemaker.