I am looking at a aircrew flask on ebay, but have no idea of its age, there is a stores number on it, 21c/1577, and a A.M. Crown ,any input would be great. number is - 152221434106 .

VERY RARE RAF VINTAGE AIRCREW FLASK,ORIGINAL. RARE A.M. MARKED RELIC CONDITION | eBay

could it be ww2 ?, looked all over the web , with no luck. thank you

also looking to find a collector of ww2 log books, I have a wrens one dated during the war. the lady died this year aged 99, found in a charity shop, does it have a value ? I await to read your reply's thanks again