[Laird Scooby]

I'm guessing we're talking about the one on ebay? It looks to me as though it's been marinised so could well be a Penta version of the B20B, possibly higher compression than the car counterpart.

I could of course be wrong but the fact the distributor has been sealed to a standard over and above most normal uses suggests precautions were taken to minimise corrosion from a salty atmosphere and/or damp entering the ignition system.