In terms of monetary value, cash on the barrel head, these are not worth much. But, as an excuse to begin a hobby that can transport you and introduce you to new people and places, these could very well be invaluable.
All these covers are recent and most stamps and prepared first day covers issued since some point in the 1930/40s don't have much monetary value above face value. (There are exceptions but these are rare, especially for GB) Stamps are issued in the 100s of millions and sometimes billions and they are everywhere. Since stamps cannot rely on an underlying commodity value to support a price, they depend on scarcity and demand and those would be issues here.
I have gone through your list and have annotated them for the catalog number in the Stanley Gibbons catalog and the value Gibbons assigned them as FDC. The reality is that most dealers probably would not be interested in these and if you were intent on disposing them, I would give
ebay a try and see what happens.
Alternatively, thing about staying and giving this hobby a try. It does not have to cost much and can be a source of pleasure.
British gardens 1st day of issue 24th aug 1983 date stamp 4 stamps and issue card, 16p sissinghurst kent house, 20. 1/2p Biddulph Grange, 28p Blenheim Palace, 31p Pitmedden, issue of stamps printed by John Waddington and son, embossed enverlope.
SG 1223/6 GBP 2.25
British fairs 1st day of issue 5th October 1983 date stamp, 4 stamps and issue card, merry go round,201/2 p rides and menageries, 28p slide show, 31p trading farm produce, Harrison and son's of high Wycombe. Embossed envelope
SG 1227/30 GBP 3.00
1983 Christmas 1st day of issue, 16th November 1983, 5 stamps, depicting seasonal wild birds, designed by Tony Meeuwissen, printed by Harrison and sons high Wycombe. Embossed enverlope
SG 1231/5 GBP 3.50
Fishing, fisherman's year 1st day of issue 21st December 1981, 4 stamps, 14p cockle dredging, 18p hauling side trawl, 22p lobster potting, 25p seine netting. Designer Brian Saunders, embossed envelope
SG 1166/9 GBP 2.00
Fishing, fisherman's year 1st day of issue 21st December 1981, 4 stamps, 14p cockle dredging, 18p hauling side trawl, 22p lobster potting, 25p seine netting. Designer Brian Saunders, (THIS ONE IS A FIRST DAY COVER with unique stamp marked) with fisherman,s year, 1981, fishmongers company London ec4 with crest.
see above. This is nice stuff but doesn't much change the value
Christmas 18th November 1981, 5 stamps, all about the post competition bbc blue peter program,11.˝ p designed by Samantha brown age 5, 14p Tracy Jenkins 14, 18p Lucinda Blackmore age 6, 22p Stephen Moore age 16, winner Sophie sharp age 8, printed by Harrison and sons, Designed by the children, embossed envelope
SG 1170/4 GBP 2.75
Christmas 18th November 1981, 5 stamps, all about the post competition bbc blue peter program,11.˝ p designed by Samantha brown age 5, 14p Tracy Jenkins 14, 18p Lucinda Blackmore age 6, 22p Stephen Moore age 16, winner Sophie sharp age 8, printed by Harrison and sons, Designed by the children, embossed envelope ( THIS IS A FIRST DAY COVER, WITH UNIQUE STAMP FROM SEASSON GREETINGS TO HRH THE PRINCESS OF WALES) 18th November 81 stamped regent street London w1, no address.
see above and no problem addressing letter to Di but a letter from Di? That'll be another story.
The royal birthday 21st june 1982.embossed silver rocking horse, embossed. special designed cover by Stewart Petty . Stamped royal birthday. Commemorative card reading a son for a princess, complete with court circular . No name mentioned , "unnamed prince".
9. 250th anniversary of Sir Richard Arkwright (textiles) 23rd july 1982, first day of issue.151/2p strawberry thief, William Morris, 191/2p Scarlet Tulip , 26p Cherry orchard by P Nash, 29p Chevrons by A foster. Published by Stuart covers ltd .Embossed.
Looks like SG 1192/5 GBP 3.00
Golden jubilee July 16th 1977, commemorative cover of the Romney /Hythe and dim church light rail way, 1st day of cover ( DELIVERED BY THE BUG!#) rhdr cover no 2 ( this date stamp was only issued on this day only) 10p Romney Hythe and dim church stamp, no 9 Winston Churchill train, queen stamped with the train stamp.
I am not sure what this is.
-Larry