Thanks to everyone who has contributed so far, it's given me lots of ideas and options.
Any that are left over after that would best be bundled into groups by theme (music, birds, plants, planes, trains) and offered on eBay that way, rather than at the 99p each that so many seem to be offered.
Ian, this may well be the way I go with it as having gone through them all this morning again it seems that they are pretty much themed around Armed Forces, Aviation, Sport, Maritime (loads), Philately and Religion.
I had previously offered some of the better ones on Ebid at 10p a cover and sold a grand total of eight so your suggestion of the trade/swap route might be better.
manfaefife - I had considered that but I've got way too much else going on already without starting another collection - Mrs JonEBoy would never stand for it
Are there any postmarks with elephants or cars?
I have been through them all this morning and not a car in site nor any elephants although there was an antelope and a bear!
I'm attaching some more scans to give you an idea of the sort of thing that is there...
Certainly even on the ones you've shown I could use the SAE to David Steel in my parliamentary collection, and the reply card with the Bermuda postmark in my postcard collection, and there are some nice slogans and so on there.
You're welcome to them - check your mail!
You can see from the new scans that whoever did these went to some trouble by using booklet stamps like the one with the Esso advert tied to a Silverstone cancel, the Eisteddfod linked to Caernarfon Castle, halfpenny blocks for the last day cancel and the 1966 issued 1066 stamp for Battle of Britain anniversary. Hence looking for a good home for these.
Of course I could just chop them up and get some pretty nice kiloware but I am loathe to do that to over 600 covers when someone has obviously gone to so much trouble to collect them.
Don't chop them up, especially the postal stationery. Even if nobody wants the special postmarks (although there must be some
demand for them), the postal stationery probably do have demand. If you cut those up, they will be worthless.
Halfpenny Yellow, you've convinced me - I won't chop them up!