RCer,

Thanks for the reply.
If you are looking at the retract from the end it would resemble a top hat.
From the dimensions that you gave me, the hat part would be 19.0 MM wide X 44.4 MM high. The hat brim would be 3.1 MM thick and the radius between the brim and the hat part would be approximately 3.1 MM. Is this right?

Looking ar the retract from the bottom it would be 47.2 high X ? wide?

Tower shows the mounting holes at 30.1MM X 38.1 MM. Is this right?

I hope this isn't too confusing.

When you mounted your retracts, did you use screws or bolts and blind nuts?
Did you recess the plywood mounts so the retracts were flush with the 1/16" bottom sheeting? If the mounting flange is 3.1 MM thick it would stick up 1.5 MM above the sheeting.
It looks as if the retract unit just fits between the ribs. Did you have to reposition any ribs?

Thanks in advance,
Greg