Decades ago these covers have been on offer for a while at a very low price. IIRC for less than € 10,-. Worldwide there must have been loads of them. I should have bought one, but... I had still mine. Then, later it came off en route, unnoticed ofcourse. It must still be lying around somewhere, hidden in the grass alongside some road. Nowadays these covers cost a fortune and I can't bring myself to buy one, just because I could have had it so cheap. I guess my hesitance to buy one now, is related to the 'fear of loss' syndrom, we humans all seem to suffer of.