It'd certainly be unique in Antelope, you just don't see HJ's or HX in that colour today. I have recorded 1 x HJ and 4 x HX Sandmans in 1894, one HX is a ute rest are vans.
Stripes would be DY1 with Antelope.

My honest opinion, do whatever you want. It is no longer original, and will no longer be the original car as the chassis is gone. Spending too much money on this one may be a big gamble. If it was me and with so much invested in the body, i'd be looking for a very rusty but original with all numbers matching 308 HX ute or van (you don't say which yours is) with the body from the same body plant as yours (either Elizabeth or Acacia Ridge for van or for a ute those two plus Dandenong and Pagewood) and using your body to restore it. It might cost you $5-7k for the car but when its finished it'll be worth twice that more than yours due to all the right numbers being there. That or buy the car that has your original chassis in it!