Spitfire R6693? and AM training film

A friend recently linked me to this multi-part training film called The Daily Inspection of a Spitfire.

I’ve seen bits of it before but this is the first time I’ve seen it in full and a couple of things jumped out at me and so I have a few questions I need help with.

First is, this appears to be a genuine 609 Sqn aircraft, it even has a couple classic ‘609 at Drem’ quirks; the 100 octane stencil on the cowling and the serial stencil on the white stripe of the fin flash. Now I’ve never seen R6693s movement card but I was under the impression this aircraft was issued to 610 Squadron and never went anywhere else prior to it’s loss in action in late July 1940?

Second is, in the cockpit interior close ups the a/c is fitted out for (and with) an electric chassis lever control and this doesn’t appear to be a retro fit. I always understood this didn’t appear in Mk. Is until quite late in the Battle. Yet this particualr a/c left Eastleigh in June and was Cat E about a month later?