There's only two notices that I can recall for the C36. One was to check the steering cable pulleys for possible cracks in the pulley mounting castings and the other was to check the M35 Engines for the addition of a sleeve for the water pump shafts to reduce the chance of camshaft failure. 

There are many improvement/upgrade  suggestions from owners on the site and I think someone published a book capturing upgrade ideas.
 

If your boat has an Amp gauge (instead of a Volt gauge) then it's highly recommended that you get rid of the Amp meter.  Mine is an '84 and had the Amp gauge.  The problem is that the wire run for the gauge is very long and as the wire ages the resistance goes up and it becomes a fire hazard over time.  It's a fairly easy mod to replace the Amp meter with a Volt meter and disconnect the wire that was being used for the Amp meter.

Don't know the year of your 36', but if it has the m-25xp engine you'll want to replace the alternator bracket.  There was a notice for this and I never got the memo....I found out the hard way that there was a notice sent out......some have found out an even harder way....we got lucky if you call it that....

From the Catalina dierct site:  "Universal alternator bracket conversion kit for M-18, M-25 and early M-25XP engines.

Replaces an earlier design that was prone to failure. Modes of failure reported by customers:

• Bracket failure that releases the alternator into the oil filter causing damage to the filter and oil loss.
• Failure of the engine's aluminum gear housing where the lower alternator bracket mounts to the housing. A crack in the housing again results in loss of engine oil."

Luckily we only lost 'all the engine oil 2/3 way down Baja and about 70 miles off shore, there were signs that ultimately led to the impending disaster and fortunately I caught it and killed the engine before the engine actually got killed...