Ian, very generous offer but rather than put you to trouble in view of huge demand (understandable–if there's owt for nowt, i'll be there wi'barra.) I might as well save you the bother and cultivate a local offset lithographer as I assume they are all glad to be rid of these printers blankets when past use.
I am aware how much time packaging and posting can take and large rubber sheets will obviously be useful in my ongoing efforts to upgrade my living quarters to a hovel. (I say "quarters", "sixteenths"would be more appropriate.) .
Should my local efforts come to naught I may yet contact you via this thread for advice or to take advantage of your generous offer but I fully expect my unscrupulous tongue will shortly mean I am awash with rubber sheets (not a bad thing to lay in for a man of advancing years) . Should I fail locally I shall of course submit the required remittance and also forward a complimentary set of soft jaws for a Pratt Burnerd 160mm chuck, a considerable quantity of which (brand new and boxed ) have fallen into my equally unscrupulous hands. That is if they would be of use to you.
This would be at least some compensation for your own generous efforts in giving up your time packaging and posting these sheets.
Very warmest regards