I can confirm, that street SWB Berlinettas also had the 539/61 Chassis (not all, but some). And after having a look, I can confirm, that there hase been chassis tipo 539/61 comp. in the SEFAC Hot Rods. In the case of 2383GT I´m not going on the info in Nowak's book. But I can confirm, he is correct with chassis and engine tipo.