RAF Chippies still had cartridge start in 1983
Make that at least 1990.
There was one at 5AEF Cambridge with electric start for some years. The starter motor I believe was ex Pembroke; we were told that lots of motors were in store somewhere, ready to be fitted. But the suppliers did their sums again and found that there were enough cartridges in stock to last until the Bulldogs replaced the last AEF Chipmunks, so no more were converted. At 5AEF, the Bulldogs arrived about 1994; the lone electric start had been there for maybe 5 years.