Needing a NOS starter switch

Morning Men

I'd like to buy another NOS starter switch - the switch that the starter rod moves through to switch the starter motor on/off. For I've just had to use the spare I had and would like to get another spare in case said switch fails in another of our HSS's . These used to come up on ebay fairly regularly but I haven't seen one there for some months (I've been watching)  So I'm wondering where else I could try for one.  Any leads on this would be very appreciated.  Thank you.