Thanks. Sorry I should have been clearer - it is the gearcase oils and stuff that I am not sure about, for engine oil I am just going to carry on using what the previous owner was running which is Shell Nautilus, available here and rather conveniently on the approved list on that NMMA website!
However as the company I work for happens to be Castrol agents I should be able to get a good price on one of the Castrol ones if I order a few cases
On the others, what would be an equivalent to:
OMC Triple-Guard Grease
OMC Needle Bearing Assembly Grease
OMC Power Trim/Tilt and Power Steering Fluid (it says a Dexron II oil is ok for that - so that is fine I can buy that from myself)
OMC Ultra-HPF Gearcase Lubricant (is this just EP90? or would a lighter gear oil like 75w80 be better?)
OMC Moly Lube (is this a moly grease?)
OMC Adhesive M Sealant (silicone sealant...?)
OMC Gasket Sealing Compound (Hylomar or something...?)
What about lay-ups - they say to use a "OMC Storage Fogging Oil" before an extended lay-up period. Is this necessary? I have never done it with anything else. Seems to be that a little squirt of 2 stroke oil in through the spark plug holes will probably do the trick - it works on everything else.
Basically I suppose what I need to know is whether it is that critical to use the right stuff in various places, as I'm not sure how cranky outboard motors are if you use something that is "more or less right". Are we talking Land Rover or F1 car here?