It's a 1916 style year Power Plus that the original owner converted to a twin engine sometime before 1924. The engine numbers are very low so I'm pretty sure it was made in late 1915, making it eligible for the Horseless Carriage Club.
 

The guy who built it married his widow (who sold it to me) in 1924, and by the time they got married he had converted it from a single engine and run it enough to put a lot of wear on it and parked it. Sometime in the 50's or 60's their son tinkered with it and got it running, much to the chagrin of the "old-man". After the "old-man" died in the 80's I got the call to help the widow and daughters (the son died in the70's) sort out a couple of acres of junk, interlaced with "pearls". Among the stuff were several Flatty engine blocks, a couple of 1934 Ford PU's, a Tuckercar, a Lambretta motor scooter in the original crate, and an extensive collection of motorcycle parts and pieces.

Some motorcycle collector had already bought most of the bike stuff before I came on the scene, but for some reason the Twindian was still there, either because he didn't want the hybrid or because the widow wanted to find a better home for it.

I spent parts of a couple of years sorting through the stuff, directing them to either "dumpster" or "swap-meet" the items. I took a shine to the Twindian and the widow took a shine to me, so it ended up in my collection. It needed some TLC, but after building a new gas/oil tank, chiselling the fossilized tires off the rims, rebuilding the carburettor, and replacing the spark plugs the thing came to life.
 

I made the local antique motorcycle meet circuit with the thing for a year or so, then turned it over to a local machinist to restore. He had it a year or so before getting a lot of the basics done, then it sat in my home for several years waiting for someone to do the detail work and get it running again.