[TR] Tr3a starters

[David Templeton]

Hmmm, should clarify, there is nothing particularly wrong with the current
starter. It was rebuilt, it is very strong :-) on occasion it does seem to
start turning then it is like the solenoid pulls the gear off the flywheel. I
know it isn't that type of starter but it sounds like it :-) and it spins
free.

Key motivation for this change is 1/ reliability insurance going forward 2/
lower stress on the battery on potentially long start cycles :-P 3/ have a
little $$$ left in the '3a resurrection budget. 4/ swmbo understands the need
for such items.

David