Despite what the name implies, the Marvel UK Reprint series "Transformers: The Complete Works" was quite short lived, in fact, it lasted just 2 volumes. The first collection reprinted the first two US issues, underneath a Jerry Paris cover, which was a re-use of the cover from the premiere issue of the Marvel UK Transformers series. The second cover was a re-use of Robin Smith's cover to Marvel UK Transformers #56. These two volumes combined to reprint the first 4 issues of the American Marvel Transformers series, which had been reprinted in mostly black & white in issues #1-8 of the fortnightly UK Transformers Comics. This means these series reprinted even less issues than the two volumes of Marvel US Collected Comics TPB collections, which collected the first 6 issues of the US run (which were issues #1-8; 13-16 of the UK run).However, unlike their lengthier US counterparts, these UK Complete Works Collections were published in Hardcover, similar to the UK Comic Annuals, making the format a little more premiere. The other change, which is one of the most significant changes ever done when repackaging the original US content for the UK, was the change made on the final page of the story for issue #4.
Now Transformers was originally just supposed to be a four issue mini-series, but it was extended into an ongoing series at some point before issue #4 went to the printer. Is it possible that the final two panels that were inserted into the conclusion here in the second volume of the Complete Works HC were taken from the original earlier script of the issue #4 when it was still meant to be the finale of the mini-series, and then drawn by a Marvel UK artist? The art for these final two panels looks different than the art preceding it, so in my opinion, this is without a doubt, new panels drawn in the UK office, and not remnants of unpublished US art that was changed last minute before issue #4 went to the printer. But was the dialog original as well, or part of a previous script draft?
That really depends on the production method used for this fourth issue, and the mini-series as a whole. Was it done from a full script? Or was it done via "Marvel Method," where the writer lays out a plot outline and gives it to the artist, they create the story and pacing from there, and then the writer comes back in and scripts the story after the art was completed. If that's the way it was done, then there would be no script to draw from, and the dialog would have had to be created in the UK office along with the art. It's clear that there was some shuffling on writer duties throughout the first four issues. The premiere issue featured a Bill Mantlo plot with a script by Ralph Macchio, who typically wore an Editor hat at Marvel, not writer or scripter. With the second issue, Mantlo remained the plotter, with scripting duties taken over by Jim Salicrup, again a creator known mostly as an editor at Marvel and not writer. Salicrup would then handle all of the writing chores in issue #3 & 4. This is a bit puzzling for me, Mantlo was a seasoned pro at this point in his career, writing and scripting an amazing run of the Incredible Hulk (one of my personal all-time favorite comic runs) as well as tackling the ROM comic. He certainly was capable of scripting his own comics very well, so why bring in editors to script the issues? 
The other thing to consider is that this was a licensed product comic, where the property itself was owned by Marvel, one would assume they wanted final editorial control over the issue, and with that being the case, they would also probably require a detailed plot breakdown or complete script before the comic was given the go ahead to complete, which leads me to assume that the traditional Marvel method was not followed for the production of these first 4 issues. I would suspect full scripts were required by Hasbro for approval, it's very possible they liked Mantlo's overall plots, but didn't like the scripting, and that's why two editors came in to re-work the dialog themselves. And if that was the case, then how far ahead were they working and getting approval? Did Jim Salicrup have a full script written and sent in to Hasbro for approval prior to the mini-series being green lit to expand to an ongoing? If so, then an earlier script with the dialog Prime ultimately has here in the final page of the Complete Works may have existed. Ultimately, the only ones who probably know were the creators themselves, and with that being almost 35 years now in the rearview mirror, it's very likely that something as small and trivial is remembered today. That said, this unique little twist at the very end of the last page makes this second hardcover volume of the Transformers: The Complete Works, quite the neat deviation from the original material, as well as presenting quite the mystery on which publishing office this deviation originated in. 
