The two "GTHO" works Improved Production racers were built as XW's, a red one in works/Coca Cola livery for Allan Moffat, who disliked the car, and the white Castrol unit for Ian Geoghegan, who committed to it as a successor to his 67 Mustang, which he felt was getting a bit long in the tooth.
They never raced as XW's IIRC, but were facelifted with XY panels. Both shells were radically acid-dipped, and built by Al Turner along the same sort of guidelines as the legendary "Trans-Am" Mustangs (of which Moffat's car was one). The gestation period was difficult.
On the basis that prizemoney was what kept the doors of AMR open, Moffat was reluctant to race the car, as it was distinctly lacking in traction, and handling-wise was never a match for the Trans-Am Mustang... and so it languished for a long time at AMR, its engine removed and fitted at one stage to the 'stang.
Geoghegan spent an awful lot of money and time in developing the car, reshelling it at one stage (IIRC) to try and restored the rigidity that went during the acid dipping, and getting John Joyce at Bowen Engineering involved. As legendary as that car was, its biggest day was Easter Monday 1972, and it garnered very little other success for Haberfield Fats. Geoghegan eventually sold it (traded it for a large-ish boat IIRC) to Kingsley Hibbard, who butchered it and shelved it, until David Bowden convinced him to part with it in 1985-ish.
When David went bust in the mid-eighties, it was the only car remaining in his collection, probably due to the notion that the creditors couldn't see any value in a junked-out old Falcon. He went on, with the help of John Wynne (the original head spanner at the Lot 6 Mahoney's Road skunkworks) in restoring it, taking two goes to get it to the condition it's in now.
The Moffat car was scrapped, but much of the componentry - such as the fuel injection system - was retained by AM (who seems to have retained a lot of that stuff - including a virginal set of conrods for the Boss 302, and the original Tunnel Port engine from the Mustang) and subsequently used in the rebuild of the Geoghegan car.
The Geoghegan car (NOT the Moffat one) was painted Grace Brothers yellow late in its Improved Proddie career, which tied in with the long-standing deal (remeber the brothers racing a Corty at Bathurst dressed in GB-supplied suits?) between Geoghegans and Grace Brothers (Leo raced a yellow Birrana, Fatty raced the yellow Charger in 1973, and Laurie O'Neill's Porsche as well).
Now for the real triva... the young designers responsible for stickering-up the Moffat car in XY trim for its publicity shots were Wayne Draper, and Peter Arcadipane. These two hoons were respnsible for many of the urban myths about big-block hardtops (they shanghaied a pair of Al Turner's 427's from the Lot 6 junkpile and whacked them in their XB's for a while). Wayne Draper did the graphics for Murray Carters XC's, XD' and XE racers, designed the "Phase" add-ons (he was a - silent, due to his emplyment within Ford - co-director of the Phase Autos mob) that formed the homologation bodywork for the XD and XE racers, and played a big part in ensuring that the XD was homologated for Group C - at 1362kg dry weight (DJ's car was the only one that got near it - for more info, read "The Unforgiving Minute".
Peter Arcadipane was renowned throughout the 80's as an illustrator, but is also the man behind the styling of Mitsubishi's current Lancer series.
And that's post# 1302... one 302 for me, thanks!