nope...
the razor edge was fitted to most 88" as standard with or without the option of a spare wheel carrier, even on many 88" station wagons
but on saying that the "deluxe" bonnet could be fitted as an option
109s all got the "deluxe" bonnet as standard, the difference came in when folks wanted to carry a spare on the "deluxe" when they then got a "dished deluxe", the "dish" being due to the bigger 7.50 tyres fitted to a 109" and trying to unblock the drivers vision
so to sum it up, you can fit whatever bonnet you like to an 88" but a 109" would correctly only be fitted with a "deluxe"
hope that helps to reduce your confusion even if not your indecision, personally i'd fit a razor edge to an 88" as it looks "proper"