The tumbler on my original Lucas switch was worn out and an aftermarket tumbler I bought would not fit correctly.
I was unable to find a new OEM tumbler. So I bought a complete new aftermarket switch complete with a tumbler
but it would not fit the mounting hole of the tang attached to the back plate of the air box. I would have had to
ream out the hole to a larger size and I was unwilling to do this. So I found a used OEM switch on eBay for a reasonable
price that had been dismantled and reconditioned and it worked perfectly. It even included the original Union key
with the key code stamped on it.
If you remove the entire switch/tumbler assembly and take it to a locksmith he ought to be able to make you a
key that works provided you bring the correct key blank. He is unlikely to have an obscure British key blank in stock.
They are on eBay frequently. All of this will probably cost more than buying a complete new assembly.
1970 Triumph Tiger
2016 Yamaha FZ-07