I recently picked up a very nice little 50 cal sidelock and need some help identifying the model. The left side of the barrel is marked Ardesa Spain 50 cal and Black Powder only. The right of the barrel has proofmarks. It is a Hawken style with half stock and one retaining wedge. The barrel is 26" and the overall length is just a shade over 40". There is no patchbox. It has set triggers. Any help with ID and suggested loads would be appreciated. I thought I would start with a 350 maxi-hunter and 70 grains pyrodex RS.