Well, having spoken to yet another very nice chap at Norwich I can report that they indeed are charging £45 for a single landing. However, I'm told if I elect to pay at the end of the month and in that time incur additional landing/parking charges then the £45 min charge will apply to the total bill ... individual landings etc being at the rate shown in their price list. Justification? Apparently the poor dears have to handle commercials out of the same terminal (just like Le Touquet / Le Mans / Deauville etc. etc.) and they've justified the outrageous one-landing charge on the basis of dissuading GA until another GA-specific handling agent come along early next years.
Wouldn't it be poetic justice if by then they had no GA to handle ...
Mike