Martin made "electric flat top guitars", fitted with this kind of De Armond Pick ups, only between 1959 and 1964.
The OO 18 E model is the only one of the range, fitted with one pick up (and two knobs)
So, and just with one pick up, no doubt that it's (obligatory) the Bruce Martin model
(Congratulations Bruce 
)The two other possible "electric flat top Martin guitars", always fitted with two De Armond pick ups are the D18E (three knobs) and the D28 E (four knobs).
The rarest of the three is the D 18 E made only in 58 and 59... (Around 300 guitars made for this model, around the double: 600 made for the two other ones)
I just would add !
About the acoustic guitars that Bruce used, it' amazing (!) to see that during the film The Young Ones, Bruce plays a VERY rare ! acoustic Gibson J 50 (Blonde..) "Banner Headstock".
You have to know that all of these Gibson "Banner Headstock" guitars were only made during three years in the early forties (43/45) and on the peghead we can read : Just A Gibson Is Good Enough (!)
And if, on the US market, it's not so easy to find a J45 (sunburst finish) Banner Headstock, hope to find a J50 (Blonde finish) like we said in french " Tu dois brûler un cierge"...
So it's the reason why it's amazing to see Bruce with a so rare guitar in his hands in 61... And, in addition, the (his ?) guitar seems to be "new" (or mint !)
Question to Bruce if he reads this post
Do you remember how you were able to get and the play this Gibson ?
Best regards from Paris
Patrice