With the relatively small amount of money involved with this transaction, I decided to explore this part of PayPal that never encountered before. I logged into my PayPal account and declined the transfer. This opened up another page that allowed me a choice either to convert and accept the transfer in US currency, accept the transfer in GBP in a separate account or totally decline the transfer. A roundabout way of doing a simple conversion but as Peter noted, a couple of extra steps, nothing onerous. I'll know what to do next time this happens.
Joji Tokumoto