I have pics of many chassis from books including the Devin SS.
None have dimensions or any ready means of finding scale.
With the current level of "OMG, these old cars are SO DANGEROUS to drive!" hysteria*** (Fostered by eco-nuts, insurance and manufacturer lobbyist, and others with ulterior motives) I doubt a pure copy of a Devin SS or early Cobra chassis could be sold to more than select few genuine enthusiast.
But I feel they still remain a good starting point, at least providing basic dimensions to build on.
*** Anyone afraid to drive their classic can donate it to me for proper safeguarding.
The 59 Chevy vs late model Chevy crash being pushed on youtube by the insurance lobby is a good example of such anti-classic propaganda.