I've managed to fill part of my own upload requests here!
(a) Find the WHDLoad version of the original 1987 DOS release in English in the Zone. I don't think it's available elsewhere as I was only able to turn up the French and German versions in the usual places (e.g. EAB FTP site, WHDownload etc).
Unfortunately, I think the slave needs an update as all 3 language versions locked up regularly at specific points in the game on my A1200/030 under WHDLoad 18.1.
(b) Find an ADF of the original 1987 DOS release in English in the Zone too. There's a cracked version in TOSEC by Delta Force (DF), but the ADF I've upped is from an original boxed copy and avoids having to go through the lame cracktro of the DF version.
Both are in the Zone. Enjoy!
BTW I'm still looking for the Spanish DOS version
of Powerplay released in '87 (ADF, WHDLoad or whatever), if such a version was ever published. The credits in-game suggest that it does exist, but the Spanish version was published by MCM rather than Arcana.......so who knows!