There's also the elusive "Gottlieb Parts and Price *Supplement* 1978 (Vol P)", has anyone ever seen that?
In comparing other machines (9 total, seven 7907's and two 7766's), I'm thinking the only difference between the 7766 and 7907 parts is the extended single post for "E" level switches. Comparing the motor timing charts on the schematics (assuming they are accurate), I see no other timing differences between 7766 and 7907 machines.
Until I find a reference, I'm guessing it's an A-7766 - because Strange World does have motor switches on the "E" level.
Thanks! Never noticed that they hid the motor cam part number in the bottom of the "Other Coils Used" table in the manual (but not on the schematic).