[mikeshilton]

Hi John,I would be inclined to insure it for between £1500 and £2500,I collect Luftwaffe flying clothing and equipment,although my interest is mid to late war,I have seen these early items go for quite high prices.If it were on say E-bay,it may go for £1000,but if two or more collectors are after the same item it could go for considerably more.
Best thing to do is do a search for Battle of Britain Schwimvest and see what comes up,a dealer may have one in stock that could give you a guide price,Regards,Mike.