Picked this one up. It looks to be in good condition. I have the key and bob. It say P. Barnes & Co. Bristol Ct. Cleaned up the case. Couple of questions. Never saw this company. Is this a rare or uncommon piece-any info on company? I am missing bottom glass pane. Any ideas on what the original might have been or finding a replacement. How can I tell if feet are original? Also saw one pic of a Barnes and it had a bell instead of a coil-should I replace it with a bell? Lastly any idea on age? Here are some pics and advice appreciated, thanks.