Right from the start, arched vintage trailer awnings are made differently from traditional flat trailer awnings.
Arched Vintage Trailer Awnings have pockets formed in the facings that surround the underside of the awning. The shock poles cross and seat into the corner pockets. dfoster@bellsouth.net
Arched vintage camper awnings have a tie strap centered on the underside, to keep the shock poles from sliding out of position.
Tie Strap is centered on the underside of an arched vintage trailer awning, to keep the shock poles from slipping out of position. dfoster@bellsouth.net
In the front corners of an arched vintage trailer awning, the pockets are hidden in the facings, so when using the awning without the shock poles the differences aren't noticeable.
The shock pole pockets are hidden in the facings on the underside of an arched vintage trailer awning. dfoster@bellsouth.net 
Image of a shock pole pocket, disguised in the facing on the underside of an arched vintage trailer awning. dfoster@bellsouth.net
Measuring the shock poles, for each individual arched vintage trailer awning, is always a challenge.
The shock poles need to be just the right length to arch the awning upward providing extra height underneath and incline for rain run off. dfoster@bellsouth.net
An arched vintage trailer awning, is suitable for the straight / level section of a c-channel awning rail. The largest arched awnings that I make are the 8' x 8'size.
