Well, I am glad to say I have the problem solved. I got to thinking that the missing barrel selector button might hold the part that slides left to right under the weight more tightly in its slot, keep it perpendicular, and therefore let the parts slide forward freely. I found a nylon washer and a steel washer and put them on the shaft for the barrel selector and found a pin to secure them. Now the hammers fire correctly no matter which one is selected first. I'll keep a look out for a source for the correct selector button. Thank you for the suggestions and the pictures. Dan
