Thanks for the extra info.
This is the first time I have seen this drum name "Sonorus"
Either way the set looks all original and with many extras including the cymbals.
The Ajax snare is a very nice example and can be sold with or without the set since it did not originally come with the drums at least I do not think so.
So with that said I guess for the entire set-up in what looks like very good condition $800 - $1600. (The drastic range is because I do not know much about the drums themselves)
In the states we rarely see these drums and they are hard to price since most US collectors tend to stay with Gretsch, Ludwig, Leedy, Slingerland, Camco etc...
The cymbals are also from a different era I think based on the image so they can also be sold seperately if you really wanted to.
If the snare, cymbals and set all were from the same era and original to the set I would not split it up.
But in your case the drums should stay together and you have the option to sell the snare and cymbals seperately.
Maybe another member has more info on them and could give a more accurate price then me.
I still would like a close up of the badge of the drums for the web site. I have the badge for the snare already
David