At the risk of sounding like an 'ERA snob' (a title held by my friend, counselor PatrickT) I would say that it would benefit the Hurricane builders and customers to compare this chassis to ERA's.
If the above drawings are accurate and do not omit any parts, there are significant structural differences between the two. Especially if racing is planned. On an ERA, the main rails are 3 x4 and the 'x' member is 2 x3.
Namely: the ERA has a larger 'x' member which runs from the door leading edge all the way to the main rear crossmember. This 'x' is one tube welded to 2 legs to make the 'x'. The H'cane shows the x rails cut short of the main rails and joined by short rectangular tubes to the main rails-obviously to lower the trans mount. ERA accomplishes that with a rectangular gusset welded just forward of the x. The trans mount sits on that pad and the tail shaft is above the 3" dimension of the 'x'. Trans comes out from the top.
The H'cane main chassis rails do not extend all the way to the front of the radiator mount. Further, the ERA has a full 'k' member front crossmember below their 'x' member, which ties the lower, rear, control arm pivot to the whole chassis. There is nothing below the H'cane front 'x' member.
The ERA has a substantial double vertical post at the door hinge/cowl brace area. The door latch on an ERA is a steel plate which is welded to a rectangular upright which ties into the rear cockpit brace. The H'cane shows no latch plate and only what looks like a 1" round tube for fiberglass attachment.
The H'cane shows no engine mount structure but an ERA has 2, 2 x3's angle welded to the chassis with flat plates for motor mounts.
A look at the diagrams on ERA's site will make things more clear than I described them. Here are two views of mine:
My car is 25+ years old, has no stress marks in the glass, has been raced and weighs 2650 wet.