What is this 1983 XJS-C that's not a real factory one?

[sbobev (Steve)]

I think something similar was discussed in this thread from last year.

1984 XJ-SC prototype, 1 of 12 made

Hi, I’m helping my dad research the history of his old Jaguar and could use some help! It’s a 1984 XJ-SC and he was told it was created as a prototype and was 1 of only 12 that were ultimately manufactured by Jaguar before they decided not to go ahead with that prototype. Does anyone know if there’s a digital archive or online database where I could verify this info? ​​​​​​​Thanks so much!