klug,
PM sent.
"Chipmunk, The First Fifty Years" says that as at Jan 1994 the Finningley Chipmunks were WD390, WG407, WK590 and WK638.
WD390 is now G-BWNK
WG407 is now G-BWMX
WK590 is now G-BWVZ (now based in Belgium)
WK638 is now G-BWJZ (doesn't seem to have a current CofA)
Those the ones you were looking for?
WF.