John:
It's very hard to find an existing trailer that fits a fixed gear glider (like the Phoebus A) because the glider has to sit so high in the trailer. There is not enough space between the canopy and the trailer top. Most trailers you will find will have a lower roof because the glider that went in it had retractable gear.

I would borrow a Schweitzer open type multipurpose trailer (with lots of straps & padding) to go and get the glider to take home. Then go on Google looking for "trailer frame kits" and start building from there.

Many fixed gear Phoebus trailers (including one that I had) used a center device that fitted to the fuselage when the wings were removed that held a garage door roller mounted vertically. The roller fit into a straight garage door channel that ran along the top of the enclosed trailer. You fit the fuselage/roller into the channel and that kept the fuselage upright in the trailer.There was no fuselage dolly. A latch mechanism on the channel kept the fuselage from moving fore & aft. Wing dollies are easy to make. Ditto for the stabilizer frame.

Good luck with this project if you do it.

ROY