Prices mentioned seem about right
check out www.pixelmatic.com.au/cortina
best cortina site i have seen. not updated often now days but hey they havent changed for 30 years.
as for little things to look for as JG33 is number for Falcon GT, 77 is number for 2 door GT and 78 for 4 door
if it has the original engine it will have the letter GT stamped on a lug on the head looking down you will see it half way down the head on the right hand side.
Make sure engine is 120E cast into block. Anything else will be 1600 (Mk2 Cortina, Escort, Capri Motor).
Body should have twin chrome strips down side forming a arrow point at front. Chrome surrounds on doors (around the windows). This is a good test cause they are hard to get off and something people forget when they create a replica.
Should have a 4 gauge pod in centre of dash with amp,fuel, water temp and oil pressure gauges. Should have a remote shift (come up from floor then horisontal towards rear of car then up for the gear stick) and will be covered by a centre console with lift up lid.
As the centre console has a ashtray in the rear of it, the GT is the only model not to have ashtrays in the rear door trims of a 4 door (little known fact and another way to pick a replica)
should have GT badging on both rear wings and boot lid.
should have arms (2) on rear axle coming from chassis rails to the rear axle.
If they are steel rims they should be 5 inch not 4.5 as standard cortinas and 5.5 as lotus had.
just have a look at some of the pics on the website under the GT section and that will show some of the basic stuff.
as far as i know there is no such thing as a 1965 2 Door GT as they were all converted to GT500s.
any questions just ask i have been mucking round with these things for years having a GT race car myself and my Dad has a real nice road going GT.