^^Not only Kingswoods have the square headlight fronts. At the start of WB (4/80) this was the case, but very quickly they put the square headlight fronts on Holden models as well (8/80 for ute and van and 4/81 for cab/chassis).
My mate has a Caprice front on his WB tonner and he used a commercial bar with the Statesman number plate surround. Looks heaps better than the big rubbered bar, and if you find the bits you won't have to find a bar as well.
Just keep looking and pick the bits up. As I said, if the bottom of your radiator support is good you can unpick the spotwelds and use the bottom to repair a rusty Statesman one which you'll get for next to nothing. Headlights with buggered reflectors are not that bad price wise, just use your reflectors although you may have to buy high beam reflectors. That leaves finding a good grille, nose panel and bumperettes.

Here is a full set of repro bars, screws, nots etc to make a Caprice grille:
http://www.ebay.com.au/itm/Holden-WB...item2324dc4a2f

Here is a Deville grille for the surround:
http://www.ebay.com.au/itm/HOLDEN-WB...item4d06ccde7d

Rust free support panel buy it now $125:
http://www.ebay.com.au/itm/HOLDEN-WB...item3a7ba14b58

Same bloke for $125 for the nose panel:
http://www.ebay.com.au/itm/HOLDEN-WB...item3a7ba15c83

Headlights $100 each:
http://www.ebay.com.au/itm/WB-STATES...item4abe5e7eaa
http://www.ebay.com.au/itm/WB-STATES...item4abe5e84dc

Bumperettes are about $165 new so secondhand you'll pay that for two:
http://www.ebay.com.au/itm/WB-States...item25740d4a77

None of that is too dear?