A lot of people are slow to jump on an order offering with no certainty of product delivery. It is human nature, however, Roseville, and Metro for that matter, are known entities and people should have confidence in them.
I have bought several sets of the interior panels/seat backs and found them excellent.
My convertible does not need rear panels at the moment but I am sure it would in the future. Just on spec I would be in for two sets of Cuda panels at $1,000/set.
To Dave's point, there are much few potential users for the convertible rear inner panels due to the much lower production of convertibles. With the way the original panels age most convertibles will eventually require replacement panels. The chances of these panels being reproduced 10plus years from now is far less than it is at the present time.
If you own an E-body convertible you would be wise to pony up and get you name on any potential order while there is interest to reproduce them. Most of us have lived through the one run and done Mopar parts reproductions. The fact is you only may get one shot after the first run fills the demand.