Sadly, although you have a later linear laser mech (CDM Pro) even the replacement for that has been superceded by Philips who are the manufacturers of the mechanism.
B&O have developed an upgrade kit which allows the later CDM Pro II mechanism to be fitted. Unfortunately it is not a straight swap of the mechanism but involves fitting a modified CD interface pcb and some soldering.
Instructions are provided in the kit, which I managed to successfully install. As I recall, the kit cost around £100 which I thought was relatively cheap. I would guess that it took me around 2 hours to fit so the total cost of repair by a service centre should not be prohibitive.
I suggest that you get quotes from dealers now that you are armed with this info. The part number for the kit is 8420016.
Alternatively you could try other dealers who may well order this kit for you to fit yourself although they are discouraged from doing so by B&O.