Hi Toby!
You are quite right, all these singles are really rare since all of them were local (mostly Holland only) and the number of copies was very scarce.
Each of these singles was released as an extra local single after the major international sinlgles.
Seabird was released only in Holland in addition to 2 main singles from Deltics (Diamonds and Raincoat):
http://www.discogs.com/Chris-Rea-Seabir ... se/7038993
Since I Don't See You Anymore was released in US, Italy and again Holland after 2 major singles (Tennis and Dancing Girls):
http://www.discogs.com/Chris-Rea-Since- ... ter/589142
Hey You was an extra single for Holland after Heartbeat, Loose and Love's Strange Ways:
http://www.discogs.com/Chris-Rea-Hey-Yo ... se/5353601
Wired to the Moon - again Holland only extra single (the 5th one from the 9-track album!)
The same with All Summer Long and Giverny singles, judging by their codes (6-digit number beginning from 1)
Gonna Buy a Hat seems to be a German-only single (6-digit code starting from 88 ):
http://www.discogs.com/Chris-Rea-Gonna- ... se/6263330
None of these singles contain any unique B-sides, and neither of them was successful. I never could understand why would record labels release such singles which never hit the big time.
To this list I can add Goodbye Little Columbus (German only 7"), Don't Want Your Best Friend (US only 7") and Spanish version of Fool 7" (Voy a Volverme Loco).
By the way I bought the blue Deltics LP for a heap of money as something super rare, but saw it not once again for sale, so not quite a rarity. US release of Water Sign with a different cover is much more of a rare gem, for instance.
Thanks again for starting an amazing topic!
Best regards
Andrey