As the owner of several combination guns and drillings, I can only tell you what I look for in such a weapon,

I browsed through Guns International's section on Drillings and Combination Guns and came up with this example, which pretty much exemplifies what I would look for: http://www.gunsinternational.com/guns-fo...un_id=100852611

The gun misses out on one of your requirements immediately, since it is post War. However, there are some distinct disadvantages to pre-War guns you should be aware of. For one, the shot barrel is likely to be 16 gauge 65mm or 70mm. This translates into 2 1/2" or 2 9/16" shells, neither of which is easy to locate. There is the option of opening the chamber up for modern 75mm (2 3/4") shells, but the barrel walls have to be thick enough to allow it.

A pre-War gun is less likely to come with a scope. This is important, because fitting a scope to a drilling or combination gun is likely to be an expensive exercise.

A pre-War gun is also likely to come in a caliber which is difficult to obtain, such as the popular "Förster Patrone" (forester cartridge), the 9.3X72R, which is strictly a hand loading proposition at present.

A pre-War gun is unlikely to have parts available, in the event a replacement is needed, which means that such a part will have to be fabricated by a competent gunsmith.

That said, what do I find attractive about the gun in question? For one thing, it is made by a well known maker, who is still in business. For another, it fires ammunition which is readily available. It is already fitted with a scope in traditional claw mounts. It has a well designed stock, and metal and wood appear to be in excellent condition. Finally, the price is in line with what I would expect to pay for such a weapon. If I did not already have a drilling in the same caliber, I might consider buying it myself.

Good luck in your search!