Going from memory here also (will be home on Sunday at which point I'll have access to everything on my home pc including a copy of the SGUK), so not sure about a conflict between different lists. Point about sub 0.5 mt strikes has come up before though and I believe that there are no references to warhead sizes in the SGUK but there are in the v2 BYB (which basically takes what was in the v1 SGUK including incorrectly listing Bantry Bay as being in the UK. Previous discussion was here
http://forum.juhlin.com/showpost.php...5&postcount=87
Reading that post again, it looks like there may well be ambiguities between the two maps in the SGUK, although those may relate more to the island of Ireland than the UK.