There are 3 different OVPs to cover all the different models that use them. Just as each car has a different alternator. The number mentioned fits cars with HFM fuel systems which the 90 model doesn't have.
The other two numbers are 201 540 08 45 and has one fuse and 201 540 37 45 which has two fuses. The 08 has 5 pins and the 37 has 9 pins. The originals OVPs might have one less pin on each. All the relays have been updated to these current versions.
Bosch Master, ASE Master, L1
33 years MB technician