Thank you mckha489 and Alan of Kaslo for getting the ball rolling, I’ll follow up the leads.
Also thanks to CarolW for kindly tracking down his will, which is of interest. I duly filled in an application and paid £1.50 but turns out there is a new system provided by ‘HMCTS’ which sorry to say is not ideal..we’ve chatted on PM about it and it turns out others have had poor experiences as well - infuriating.