Attention Thorens experts

I have a 100% stock Thorens TD-166 MkII with an extra arm wand. I had my current cartridge, an Ortofon OM-30 Super, professionally mounted. I assume the VTA was adjusted by the shop (a reputable local hifi store). I am thinking about putting a new cartridge on the second wand, probably a Denon DL-160. I am not very good at these things, but I think I did once mount a cartridge on this 'table (I've had it for 26 years, since new).

My question involves VTA adjustment. The owner's manual does not mention VTA adjustments at all. However, I see several philips head screws on the tonearm mounting plate. Are these used to adjust VTA? If so, how? If not, can the VTA of this arm be adjusted? If so, how? When answering, please keep in mind that I am neither skilled nor experienced in working on turntables or tonearms. Thanks!