Little V

Can you imagine, no mixes, no reversing, servos came in 2 flavours, red or black, depending whether you wanted normal or reversed!
Of course, Garry was a boy then, aside from me he's about the only other one who'll remember!
Back on topic, that fuselage looks the bees knees, is that paint or cover of some kind?

You may find that the shallow V causes a lot of 'fish-tailing' in flight, as well as anti-roll, as mentioned, ie give left rudder, the model tries to roll right.
Regarding the mechanical mixers, there were two other options - one was a pair of 180 bellcranks on a common pivot mounted in a rocking frame pivoted at the bottom, which was screwed to the fuselage.. The top of the frame was coupled to the elevator servo, and the top of the two bellcranks coupled to the two sides of the aileron (or flap) servo. the bottom of the two bellcranks then connected to the surface. You would probably have to draw it out to see how it works.
The other way I still have an example of -

It follows the same principle, the triple ball can turn with the aileron servo, or rock with the elevator servo, or of course, both at once! The centre ball connected to the elevator servo, and the two outers to the control surfaces.
The sliding servo method was prone to be very sloppy in operation.

OOPS! Spot the deliberate - those pics I put on are the wrong ones, that's for a sliding servo arrangement! (Equally sloppy). I'll have to look for the rocking ball one in my junk-box.