Probably 2 track in this era. This recording and the Dortmund one of the same year are pretty ropey in mix, but guess the aim was to make DS sound good through equally bad tv speakers of that age.
I'm hopeful the 1985 Westwood 1 recordings which were destined for radio only were multitracked. I've found photos of a mobile recording facility they used for these shows. Basically a giant converted coach, equal if not bigger to the Rolling Stones mobile used for Alchemy and Wembley 85. Just ignore the "where are the tapes" bit for one minute.
Just for information, if you listen to any bootleg from 1980, the tone is the same as Dortmund 80 and in 1981, the timbre is not much different from Werchter 1981, very thin and dry tone. (1980 has the worst tone of MK's guitar, in my opinion) In my opinion, this is because Mark was looking for the ideal timbre for his new guitars, Schecter, he was still using Musicman amps live in 80-81, this configuration generated this timbre of this tour. Mark only found the timbre he wanted for the Schecter live on the LOG tour 82-83, when he started using Mesa Boogie amps, where, the sound changes for the better on his guitar, it becomes much more imposing, in this sense, Alchemy was created at the right moment in DS's trajectory.