Thanks. I probably should have looked that up in the Scott Catalog to note that there were two different varieties of that aerogramme, the one scanned being issued on December 13, 1971.
Actually, now that I look at it I do think this variety requires a bit more explanation. The reference in the cachet stating "
Corrected Version" is a bit misleading, as no error and later correction was involved; the reference really should have read
"Modified Version".
In fact, while the Scott Catalog notes the difference between these varieties is limited to the word "AEROGRAMME" added to the description, and the folding instruction changed from all capital letters (UC44) to both upper and lower case letters (UC44a), as noted in the Postal Bulletin of 12/9/1971, there was a bit less obvious modifications made as well (see yellow highlight):

Since the Scott Catalog fails to mention these more subtle differences, I wonder how many collectors overlook these details (unless, of course, you are a postal stationery specialist)?