Rarities (5)

Johnny Todd - Pink Cadillac/Al Urban - Looking For Money
Ace PROMO 6, 1981.

Cool rockabilly two-sider, that I've only recently located. The first four "PROMO" 45s (all on Chiswick) are relatively common; Count Bishops (2), Radio Stars and Johnny Moped, but this clearly indicates that the numbering system was kept in use for Ace releases. So the obvious questions are; what was PROMO 5, and was there ever anything beyond #6?