There was a recent discussion of a Lennon signature claimed to be from his appearance at radio station WFIL's Helping Hands Marathon in May, 1975. This prompted a suggestion that we should have a signature study of Lennon's sometimes difficult to authenticate post-Beatles signature. Some examples from this period are highly abbreviated.
I'd like to start by focusing on that May 1975 signing appearance with exemplars that are believed to be from that 3-day period. What would be particularly helpful would be examples from catalogs that go back a ways.
Here are a couple of WFIL signatures from Meet the Beatles For Real, one of which includes a doodle.
Here's a group of check signatures from 1970, sorted by date - April 8, June 3 (2), July 7, October 14, November 12 (3).
A few more from 1970:
Here are all of the examples I've seen that are known to be from 1973:
The abbreviated 1980 signature on copies of the Double Fantasy LP: