The C1 came from the USA as a 'Cowl Chassis', and the cab and ute body were then made in Australia by Mitchell coach builders. I've tried looking online for any info about this company but no luck so far, does anyone on here know about Mitchell bodies?
I'd rather have tools that I don't need, than not have the tools I do need.
Good old Trove (Aust newspaper etc search engine from the National Library) came up with this as a start:
The Herald, Melbourne, 7 Oct 1936,
"Commercial Body Builders' New Works
Alf. A. Mitchell Ply. Ltd. specialises in the production of commercial bodies, and the business has developed with the growth of the industry generally.
Founded by Mr Alf Mitchell 15 years ago, ... opening of new body-building works ... in Kavanagh Street, South Melbourne. ... The old premises in Flemington Road will be devoted exclusively to repair work. ...The combined activities of Alf. A. Mitchell Ply. Ltd. now provide employment for over 100 men."
Edit: From a later advt, they were at 55 Kavanagh st, and the business name was Alf A Mitchell Pty Ltd. (There was also an A Cameron Mitchell in charge of Ruskin body builders around the same era.)
Further Edit: the original North Melbourne address was 49 Flemington rd. It appears that the business was still operating as recently as 1956 at 51 Kavanagh st.