You could make your own, someone posted these measurements some years ago on this forum with the attached PDF.
Base 142.5x117.5mm
Top/Lid 144.5x119.5mm
Front And Back 142.5x137.5mm
Sides 117.5x137.5mm
Lamp Beam Ports are 24x32mm and 48mm from the top
The four locating lugs are 4mm from the bottom/diffuser
Bests,
David.
www.dsallen.de