Never under any circumstances belittle grey auto primer.
Saved the day on this occasion and I was never told
if they wanted any specific colour and
seeing as how pretty much every single one
I had ever seen was grey then that was that.

Models always have that extra something when cased so that was the deal here,
only thing laying about was some 1mm rigid sheet,
a few cuts and fold, glue tab 'A' etc.
and a quick wrap with the old faithful self adhesive alloy tape,
a copy and cut for the company logo
on the base and sorted.