and i have been very careful to keep them away from any segwit contamination...

If that's the case, anyone can taint your legacy coin simply by sending you a donation from a segwit address. See this one for example...

https://www.blockchain.com/btc/address/1andreas3batLhQa2FawWjeyjCqyBzypd

Seems Andreas Antonopoulos isn't worried about that taint or has been sending them off with coinjoin or mixers.