The Bounty replicas built for the Marlon Brando (1962) and Mel Gibson (1984) movies are different ships. The Marlon Brando version is indeed longer than the original - the extra length being incorporated as a means of accommodating the Cinemascope cameras and Mr. Brando's ego. It deviated from reality in many respects - the deck furniture, the absence of the little water closet on the quarterdeck, and the configuration of the windlass, among many others. And, for some reason I've never seen explained, the movie people decided to paint it blue. (Quite a few artistic renderings of the Bounty made since then have given her a blue hull. I've never seen any historical justification for that color scheme - or any picture of a blue Bounty prior to the builing of the replica. Blue paint did exist in the eighteenth century; I suppose it's conceivable that she did have a blue hull. But I'm not aware of any documentary justification for it. And I know of no artistic rendering of her with a blue hull that wasn't painted after the movie came out.)
That ship (which I tend to think of as "the blue Bounty" has been in quite a few other flicks, including the Charlton Heston version of Treasure Island and, I believe, at least one of the "Pirates of the Caribbean" movies.
The Mel Gibson one was built (apparently in quite a bit of a hurry) with, as I understand it, a steel hull sheathed in wood. It actually looks pretty good in the movie, to my eye at least - the biggest deviation being the bright white (obviously synthetic) running rigging. Apparently the people responsible for the design of this one had at least some idea of how to replicate a real ship. On the other hand - as we've established earlier, there are two sets of contemporary plans for the Bounty. This replica obviously was based on the wrong one: the one drawn before the Bethia's conversion to carry breadfruit plants. Hence the absence of the water closet, among other things - and the fact that a copy of the wrong inboard/outboard profile is hanging on the bulkhead next to Anthony Hopkins's desk.
I haven't heard much about that most recent replica lately. When I was in San Francisco in 1984 I remember seeing an item in the local paper to the effect that the ship had been seized by the local authorities in conjunction with a drug bust; that's all I know about that story. I think I read something fairly recently about the ship being in bad shape due to high-speed, low-cost construction methods. I don't know whether it's still in existence or not.
For my model I used the spar dimensions that were published in the well-known article in The Mariner's Mirror, back in the thirties. I don't remember exactly what source the author of that article was quoting, but it was an Admiralty document of some sort. A few changes were made to the sail plan before the mutiny. Bligh ordered the mizzen mast shortened by several feet (I don't remember the exact dimension) while she was at Capetown. She originally carried studding sails, but Bligh concluded that the lower ones were "too long," so he "cut them and made a royal out of the canvas." My model has the "final" spar dimensions (I was trying to represent her as she looked at the time of the mutiny). I put the royal on the main mast, which seemed the logical place for it. If (gawd forbid) I were doing it again, I'd probably stow the royal and its yard inside the main topmast shrouds. At that period it was normal for royals to be "set flying."
The lineage of Bounty kits would be an interesting study. It's clear that this little Pyro/Lindberg version owes a good deal to the old Revell one - the grandaddy of all plastic Bounty kits and, in my opinion, still the best. (The competition isn't exactly distinguished.) In addition to the odd, spurious pinrails abreast the foremast, it reproduces Revell's distortion of the knee of the head. (The real thing, as represented in the Admiralty drawings, has a subtle ess-curve in profile that Revell thoroughly botched. So does the Pyro/Lindberg version - and that's not the sort of mistake that two people make independently.) Yet Pyro made an attempt (albeit not a very successful one) at the copper sheathing - which Revell missed. (That's a shame. In that same year, 1956, Revell did a better-than-passable job with the copper sheathing of its 1/192 Constitution.)
My poor old brain remembers one other detail of the color scheme. The Bounty had, as Bligh put it, "a pretty figurehead of a woman in riding habit." (The original Ms. Bethia?) The Tahitians, never having seen a European woman, found it fascinating. Bligh noted that "I ordered it painted in colors, and they sat staring at it for hours." That seems to imply that the figurehead was originally one color - probably white.