I don't like to ask for appraisals, but I'm worried that I will lose out due to my own ignorance. I know very little about my Grandfather's watch, except that he bought it in the early 1940's and wore it throughout his RAF days. It's not really to my taste, and it's a little too small for my big wrists. It's approximately 36mm in diameter. Its has a triple calendar (day, date, month) and a moon phase complication. It all works and keeps good time. Can someone please give me a rough estimate of it's worth. I've been offered £100 so far on eBay. Is this a reasonable offer? Thanks in advance!