set me straight....

[ebb]

Well, it's obvious you can't move the Pearson bulkhead back. to reclaim
your bridge-deck. And I would think the dinette is a great thing to have.
And you may even have what every woman wants: an enclosed head,
which is way more than what a stock or remodeled Ariel has to offer.
You probably also have in the 27 more headroom. A lot of plusses!

SUPPOSE you remove the rear deck hatch and push the cockpit aft maybe 16-18"?

In other words put a bench across the back of cockpit.....in back of the tiller!
You'd still have the tiller coming up at the base of the seat front.
Seat lid would still give you storage, and you'd have a small aft deck for
chocks and cleats and pushpit. Probably don't want that big ole hatch anyway.

A little complicated, but someone handy could make a short job of it.
Only problem is how you rig the mainsheet.
My A338 is highly modified so that I have no place for a traveler at boom/cockpit end.
Original rig was an "A" sheet with a single double block on the boom and singles
on the quarters. Imco you only want a traveler if you're racing on the weekends.
You can go with separate p&s purchases to separate blocks on the boom-bail.
People who have done this say the set up is equal to a traveler.
Of course there are many ways to rig the sheet. Maybe not a problem for you.

If the dinette option pushed the cabin aftwards, you may be able to place a traveler
over the companionway (on top of a dodger?) to a midboom or 3/4 boom/block position?

There you go. Don't even have to mess much with the aft cockpit bulkhead. You
are merely (I say that advisedly) lowering half of the rear deck to seat height.
And getting rid of the cumbersome hatch. No problem!
But remodel should produce what you want: at least 6.5 feet in the cockpit.
Most sailors want an outdoor place to lay down, nothing better than the cockpit.

Your Bristol has 8' beam which makes the volume very much like the Ariel.
Maybe the 27 is actually a stretch Ariel - with a very Bristol cabin top.
Haven't found the weights to compare. Some mention the boat is a little tender.
But maybe that wasn't experience talking, Albergs like to sail in the groove.

With extended seat space , you maybe can have one passenger behind the tiller,
so swinging the tiller better won't bang into too many knees.
Also, might change the tiller to an 'S' pattern that swings naturally over the seats
and without having to lift it over most knees sitting on the seats. Safer,
Had a nice one made for A338. Opens the cockpit up. More friendly.
And the better shaped tiller is not as radical as it sounds.