Accepting the fact the the hogshead and wide band are different, are there any common parts, internally, in the earlier (23 i.e.) and later transmissions? Thanks...
Only just about everything else.
Looking at internal transmission parts listed in the parts book, only eight of the forty-one items are for 26-27.
You can put '26/'27 clutch discs in any year. But only '26/'27 (outer-spline) discs will go in a '26 or '27 brake drum (unless you do a lot of difficult trimming on those hard-steel discs). The driven plate MUST match the brake drum. A few other parts are slightly different, but will mostly work interchanged. Swapping the brake pedal in almost any direction may require modification to the floorboards or pedal arm. Otherwise they will function.
If you put a later transmission or brake drum into an earlier engine/pan/hogshead, it usually is not necessary to cut the drum back, if at all, only a little bit (most people seem to cut them back too much and lose part of the drum surface). The drum will fit into the pan. If you want the larger brake in an earlier engine/car, the later drum and hogshead and band MUST ALL be used because of shaft spacing differences and requirements. An earlier pan would require some reshaping and stretching.
You should not under almost any conditions use a wide brake band under a narrow brake hogshead. Also almost never a late hogshead over a narrow brake. This is also due to the spacing differences.
Drive carefully, and enjoy, W2
Don't do it. In addition to what Wayne Sheldon has listed please see the following:
The push rings are different, The three thrust washers are different from the 09 to 16. Some of the bolts in the clutch plate are different. The brake bands are different. The magneto posts are different. Your slow speed adjustment screws are different. Your pedal support bolts are different. The push ring adjustment screws are different.
Again, Don't do it!!!!!