Can't find identifying plate on sailmaster 8.0

[Macgregor sailor]

We bought a Macgregor sailboat with a Sailmaster8.0 seahorse extended shaft motor. We have looked everywhere to find a plate with the year, model or serial number on it and can find nothing. How can we identify the year for parts and manual. The boat is an 89 but I don't know when they added the motor. The manuals go 80-89 and then 1990-2000 and it could fit in either. We did find where the sticker should be and you can see an outline of it. On the motor itself is the numbers 396556cav1

 

[Vic.S]

My '84 Yachtwin has the model number stamped on a core plug on the stb'd side of the block, hidden behind the HT coils. I can just about read it but if you have a later model with a single HT coil assembly ( mine has two separate coils) you probably won't be able to without removing the coil.