While I have been waiting for the clouds to clear I browsed the net for 8x50 FOV statistics.
They are all different!!! By googling I was given figures of 345, 336, 252, 420 etc.
EVERY site I went to had a different FOV figure for the same right-angled GS 8x50 finder!
Definately makes Geoffs idea the best way. Once I get the stars in the FOV in my finder I will do a drawing of it, compare in CDC, then I will know what my finders FOV is!
Sheeesh, and I thought this had a simple stock-standard answer.