They are neat guns. The reaction on peoples faces when the gun is operated is always fun. I have three of them, one with a solid raised rib. All of my guns have parts related to the bolt broken. I plan on making some new parts for mine this winter. I havent seen one that was not takedown. Are you saying the frame is solid and there is not a little button on the right side (behind forend)? They made a folding gun (Click here for pics of burgess folding gun) and the takedown version but I didnt know about a solid gun. The guns are pretty rare and Id think an engraved one in shootable condition would be worth upwards of $1500 and higher with condition.
Ross