Yep - you're right - a Glocker. They apparently made 6 that were considered the first 550's.
The one pictured earlier (and below) was a 4 cam coupe built for the Mille Miglia. But apparently it wasn't finished in time and didn't make the race. It's for sale tho...
Translation?
The unusual door/roof design was to facilitate access with a race helmet on
