Xosé, I went back to Mark Lewisohn's The Complete Beatles Recording Sessions: The Official Story of the Abbey Road Years. The entry for 18 July 1963 indicates three takes, two of which were complete. The entry for 30 July 1963 indicates Till There Was You remade with Ringo playing bongos as Sir George Martin felt the full drum set on the previous takes was a bit overpowering. With just this information available, it would appear that the takes on 18 July were with John and George playing acoustic guitars if drums on those takes were indeed obtrusive.
I don't have any bootlegs of these recording sessions and I'm not sure if any exist. But I'd be curious to hear a studio electric take of this song from this period.