Hi!

Congrats on that nice find! The Rado Minister is a very rare bird, this is just the second one I´ve seen inner many years. The other one is the green dialed one in the register on mission-rado.de.
I have just a very little info for you. From what I can see on your pics, it s looks to be all original and in reasonable condition. The 12120 on the back is the reference number, which dates the watch before 1972, when the 8-digit reference numbers(xxx.xxxx.x) came. I assume it´s from 1970/71 with a nice ETA 2789 day/date inside.
You should have it serviced(cleaning, oiling, adjusting) if you want to wear it regularly. Little scratches on acrylic crystals can be polished out easily with a peace of cork and some chrome polish. Nice that the original crystal with the little anchor is still present. Enjoy it and wear it in health!

I´ve put the two threads together as they´re about the same watch.