I was lurking on your site and thought maybe I would see if my Buco Twinmasters might be of use in the saddlebag section.  I assume you may know a lot more, but I am going to send what I think I know, and you may digest it at will!  I don’t know a lot about “JB,” but here is what I have.

His name was Joseph Buegeleisen, and owned “Buco Joseph Buegeleisen Co. Detroit” you can Google for yourself if you like more.  The bike pics I am sending are for the Twinmasters, and they are on my 1966 R60.  The bags are fiberglass.  I am not sure, but it appears they were only sold in white fiberglass, and everyone painted them to match their bike.  It appears JB wanted his logo on everything produced.  The rivets that hold the bag support plate have the logo on them.  Even under the hardware of the latches on the fiberglass lids, his logo is there.  The Buco mounts on this bike are a 4-point system.  Mount points are; Rear fender pivot bolt, the bottom of the shock cover bolt, the muffler mounting point, and the outside edge of the fender at the top center.

On the Twinmasters, he used a push pin system at the top with a roll pin to twist and lock the bag on.  On the bottom, he used a spring clip that would grasp the bottom support bar when pushed down to hold it into place.  Not sure if common for the time, as my outside lights act as blinkers.  Don’t know if that was common wiring, but assume not?  I have only seen a few wired that way.  OK, hope that helps.  By the way, I will send a follow-up email with pics of some Bucos that are all in original fiberglass white and some other mounting bracket systems of which I don’t know who made them but have seen them used a lot with a three-point system (that have a striking resemblance to the Wixom mounts) that eliminates the top fender mounting point of the Bucos.  Look a ton better, in my opinion, not a bunch of bolted-together pieces.

Doug

/2 bags and mount photos provided by Bob Fee, thanks

A key for a Buco bag.  Photo by Doug, aka 00weel