Hi Ed: When I jump in about similarities between the H36 and H37C, its for topics where either I've observed or make an educated guess that the two models are likely to be common. Such as the toe-rails and stanchion construction (a 37 at another Sausalito marina is the exact same as mine except if I measured maybe there's a few inches difference in the length of the toe-rail). Or that the core material for deck, cockpit and cabin top is likely to be plywood squares. Or that our boats both have (or had in my case) the anti-turbulence flaps over the gap between the hull-skeg and the rudder. The boats came from the same manufacturer and had production run year over-lap. Only makes sense the much of the construction methods were the same.
But I do know that the two models, aside from the obvious dimension differences, are also very different in overall layout and design. I read most all the 37C threads, but only participate if I think I might be able to add something or if the discussion leads to something that might also be of use for my H36.
From what I've seen on YachtWorld For-Sale photographs, the 36 and 37 interiors are laid out very differently. You are correct, my H36 does not have an aft cabin or berth. On the aft starboard side, the space that would open up from the interior to under the starboard cockpit seat is separated from the interior by a bulkhead. The electrical panel and the nav station is mounted on it. From the cockpit, lifting up the starboard seat reveals a large empty space. Stuff can be stored there. I leave it uncluttered, except for my fenders when I'm sailing. Climbing down into this area, and taking out a removable part of the engine box, I have great access to the entire starboard side of the 2QM20 engine, the steering gear under the pedestal, and the stuffing box. I have seen some 80-82 H36 pictures on YachtWorld where this starboard space is used for a berth. Ridiculously small for that purpose. I would much rather have the engine access! Another feature of my H36 in the cockpit is that a good portion of the floor is actually a removable hatch right above the engine. It takes about two minutes to remove all the screws so that the hatch can be lifted. If ever the engine needs to be removed, or I need to do something like replace a head gasket, its no problem. Replacing my exhaust elbow was a snap. The drawback to this hatch arrangement is its prone to water leaks. I've made some modification to the original design that has stopped them. But I have to remain diligent! For a 36' boat, the seating space in the cockpit is small. I'll try to remember to send you the measurements. But the interior, at least to me, has a roomy open feel to it. Hunter claims 6'5" of head room, 1" more than the 36C. I'm 6'4". I don't need to stoop at all to walk around.
Don: Yes the 80-82 H36 mast is deck stepped. The compression post underneath is a standard plumbing grade galvanized steel pipe (3" - 4" diameter). The base rests in the bilge where some rust has developed. But picking around with a sharp awl, my base still seems to have strong steel left. The bilge well on my boat is quite deep and has a good aft-ward slope. Previous owners used just one bilge pump and the float allowed 2-3" water as the normal level which would slosh up around to the compression post base. I have added a micro bilge pump very far aft which keeps the water level at about 1/2" and at the very aft only at that. The forward 4-5 feet of the bilge is now always totally dry and the compression post base never gets sloshed with seawater. I'm hoping that I'll get many more years out of it. As for how the boat sails, I really don't have much experience on other boats. However, friends that have multi-boat experience say they are impressed with the manners of my H36. (Of course they may not want to hurt my feelings.) I do observe that I seem to be a few pointing degrees disadvantaged compared to other mid/large cruising boats on SF Bay. The boat is designed for toe rail jib sheet leads, which I have maintained. No inner track. Another factor is that my sails, while still visually presentable, are many, many years old and surely stretched out a lot. A new head sail in particular would probably add back a few degrees into the wind.
For JC: I enjoyed your recount of the 80-82 H36's method of conception. Bit of a shot-gun wedding! As you included in your post, the 80-82 36 does have some qualities. Many people and things from unorthodox or unplanned lines of heritage turn out quite well.