Miller,
Please excuse me...my mind is still reeling from the scope of Pete's undertaking...he's got his work cut out for him...the USPTO patent threads are tragically fractured and temporarily incomplete...I've found patent numbers cited in other patents that do not occur in the patent classification thread...then when I do a full text search and view the patent, suddenly it finds its way into the classification thread at the USPTO...
Until the patent office completes filing all patents into their respective threads, Pete will be adding names/patents for years to come.
The double gun evolution alone had at least 750 patents before 1950...and I have a file of recently located patents not yet added (maybe 8 or 10)...I think I gave Schuktnecht about 600 patents before Chris turned that deal to mush causing him to publish prematurely...(there's a joke in there somewhere)
Pete,
I have some home made cross reference material that may help you to cross check your database...whew, I thought I had holes to plug...I have 16 Lefever double gun patents (DM & CF) (not air rifle patents) plus at least 3 other patents drawn on Lefever SxS's...plus the Dangerfield patent that you listed(130984)...bringing the total to 16 or 20 depending on how you look at it...as soon as I come across that firearm reference material, I will take digital photos and contact you...please excuse me while I immerse myself in Pete's database for a couple of days...
Thank you Pete and Miller