First move would be to contact Wheels of Time and see if you can get a couple roofs to piece together.
Something I did for a roof with a little different profile was to use a router. I had then hand-notch the end to fit over the doors.
If the right size router was available, maybe you could get something close.
One final option could be to have it printed. Could probably get it around $12 (plus shipping) with the expectation of sanding it to smooth it out.
Jason