835 with secondary mark of Crown 3 rings and S C

[Silver800]

I have this spoons, well its actually a set of spoons I recently came into possession of that have this interesting mark that I am scratching my head on. I have both volumes one and two of the Worlds Hallmarks by the hallmark research institute and haven't been able to find this mark in their or online with much success.

I can only assume that because the purity of the silver on the lower mark is 835 that it is probably European in nature however even that I'm not certain of

the 835 mark on all the spoons are in the same orientation however the crown I've noted has been in this position as well as turned on a 90 degree as well as a full 180 degree from the position shown. I'm using this image however as it is the clearest hallmark I have with the most detail.

any help would be greatly appreciated!