Hi Jules,
Welcome to Birdforum, hope you enjoy things here. There is a Yorkshire section
here
Please accept my condolences on the loss of your husband.
I would second Delia's suggestion of using the classified section here once you are no longer a new member, when you do put it up for sale, say exactly what the Leica is, as that brand would cover cameras, binoculars and telescopes. For cameras you need the model name and number, binoculars and telescopes need model name along with magnification and lens size. Once you have put your ad in the classified section you can post in the Yorkshire section about it, pointing the guys to it.