Was browsing ebay about 2 weeks ago and saw this just listed 21j Bunn Special and noticed the early serial number and different pattern finish, had a low buy it now due to the seller having snapped off the winding stem when opening the watch to take pictures (was in a Philly 20 year gold filled flip open- I placed in an sligthly later case for photos and to make sure it worked ok- gotta hunt down a replacement stem). My hunch was right I believe, and the Bunn Special 16s book by Michael Chamelin definately paid for itself here! I confirmed the serial #2576898 was in a run of only 100 bright spotted Bunns that had the "double roller" spelled out completely under the balance! (#2576101 to 2576900) He lists only a very few known serial numbers at the time of the books publication for survivors. (hope its ok to share this info?) The Montgomery dial also looks to be correct and original for the watch as well (a few hairlines but not bad for over 100 years old). Will have to look for the correct stem to replace and get it back into its original case somewhere down the road (although I hate flip outs). Watch is running great and keeping very good time, but sometime in near future will give it a cleaning and oiling. Just thought I'd share!