Hi SB; can tell you something about the amp ... not so much on it's tone. These are pics of a 200S formerly owned by our BBer matsickma:
There are a couple of LTG threads
here (including a link to pics of the original owner's manual) and
here. Our member Emperor-TK drew a cleaned-up schematic and it can be found
here.
The 200S is two separate amplifiers on the same chassis with two sets of cathode-biased EL34 output tubes, two output transformers, and two 12" speakers. The control panel has a stereo jack that will feed each amp; if you have a true stereo input ... that is ... independent Left and Right signals, the amp's output is stereo; one channel from one amp, the other from the other amp. Otherwise, if the input signal is from a conventionally-wired 'mono' guitar as most are, the output is dual-mono ... same signal from both sides however still with the 'stereophonic' effect of left and right signals.
One of the linked threads was started by our member NMiller. You can PM him for his comments or try contacting him on the
Chicago 51 Valco BB (off-line as of this post) or
The Gear Page. Also, you might contacting our member
matsickma; he really knows a lot about the 200S and many other Guild amps. Good luck!