HST was a Shelby subcontractor - they made fiberglass and the very few carbon fiber cars. I would suggest you contact Gary Patterson at Shelby American - GaryP@ShelbyAmerican.com
First, HST is no longer in business. All of the molds and tooling was recovered by Shelby American and brought to Vegas.
I'm not sure what part you need since the Cobra body is pretty much one piece (except for hood, doors, trunk lid). The car is a Shelby Cobra (CSX series) so I would recommend you contact Gary Patterson at Shelby American in Vegas. Chances are they will need the car there for repairs.
You might find a really good fiberglass (I'm assuming yours is glass and not aluminum) locally though, but I'd want to see some really good references.
Likes Received