smkummer:
Welcome to the board. That the Simson handles better than the Winchester 24 is not surprising. The 24 is a sorry example of a double gun - was made to trade on the Winchester name and not on any merit of its own, which it has little.
As for your gun. If the gun is a DDR made post WWII gun, it will be valued at a good deal less than a prewar gun.
Look at the proofs, appearing on the barrel flats and action flats. Should have a "Crown over U", a "Crown over W", a "Crown over S", a 20 in a circle, "Crown over N" , there should also be the "Crowned Imperial Eagle" ( a non-sequitur for a Commie country, but thats what it was), a three digit number which will be the proof date month and year. There may also be, a "Q" with a number 1 superimposed on it, signifying "superior quality", or a triangle with the numeral 1 , signifying first quality.
A DDR - made gun is not as much in demand as a prewar gun, and I would expect even a plain unembellished 20g to run around $800-900 or so. If you get an offer on 1000 or so, take it and run. O f course, thats my opinion, and others may differ.
Hope this helps a bit.
Regards
GKT