Not wanting to start a debate about whether or not to fit indicators, but if fitted, what do people use as an appropriate period looking switch, and where do you locate it?
You can do this in a variety of ways but my choice is to fit a 3 way toggle switch on the back of the dash in a position that suits you with the end of the switch just protruding under the dash. You can either use one with a coloured end that lights up when activated left or right or a plain black one and fit a separate indicator lamp. I usually do the latter and fit this behind the dash inside the steering column cut out on a small bracket where it can be clearly seen.
Thanks, Terry, your suggestion of putting the switch behind the dash with just the tip of the lever showing is a good one. Perhaps it might be best to opt for one of the self cancelling ones?
Why not use the original indicator buttons on the dash with concealed relays to provide a latched relay that is cancelled by a small push button mounted as TH suggests?
TH is spot on! I have used his method on a number of cars, not only prewar MG's, but also my 1912 Rover and 1910 Humber. I have also added "after-market" stop lamps to the older cars. None of the older cars had "winking" direction indicators or stop lights (in fact the Rover and Humber had acetylene/paraffin lamps) but I live in dread that some (young?) driver will run into the back of one of the cars! As a matter of interest I also added a small "beeping" unit to the direction indicator set-up which emits an annoying sound when the lamps "wink" so I return the switch to the off position without delay once I am around the corner.