The value is really dependent on the presence of the correct (mostly date coded) parts and attention to detail. High end cars will have NOS/original shocks, either NOS or Scott Fuller repro exhaust system, Autolite gas cap, etc. etc.
The big ticket engine bay items are (ignoring service parts):
1) Autolite 4300-D carburetor unique to B1. I've never come across a correct carb stud for sale in 15 years. Has a small plastic bead in a hole as a locking device for the wing nut.
2) Carter 4841S fuel pump.
3) Autolite twin point distributor - without a mirror impossible to see engineering no. Vacuum advance is wrong '70 style with rounded nose and press-in front nipple. Should have the cast in front nipple and wide gold band.
4) Autolite ignition coil - stamp should be a silver/white ink stamp and mostly there are two small numbers between the two terminals . Decal/sticker suggests repro coil.
5) Engine governor (rev limiter) - very few valid date codes (format yy/ww) for these as they were produced in infrequent batches.
6) Voltage regulator (repro are identified by the ink stamp being too crisp and/or cover wrong shade of blue). Ink stamp will be white/silver
7) Starter solenoid.
8) Radiator.
9) Air cleaner assembly.
All these pieces are date coded, except I think the air cleaner assembly, although there are markings on the flange.
The other big ticket items in the engine bay are the radiator cap, Ram Air seal, air filter element (there's still ongoing debate about which was factory installed - the FA50 (various versions over the years) or a non-identifiable filter), battery cables and top to windscreen washer reservoir with correct eng. part no ("BA" not "CA").
Other observations:
1) Top radiator hose clamps are incorrect. Should be wire style.
2) Front fender bolts inside engine bay should be plated.
3) Boot mat should not be present.
4) Spare tyre should be mounted on passenger side with air bottle under tyre. A spring secures the air bottle.
5) Caution fan decal on radiator shroud was not installed at the factory.
6) Wrong finish on hood lock plates (should be plated).
7) Maybe wrong finish on shock tower braces (should be slop grey).
8) Paper decal on valve cover is very likely incorrect.
9) Ordered with trim rings and hub caps.
10) Engine bay inspection decals are repro.
11) Sewn cover on steering wheel is not a factory item.
12) Wrong decals on top side of hood. Should be "RAM AIR".
13) Heater hose clamps incorrect. Should be date coded Wittek tower style.
14) Voltage regulator looks incorrect.
15) Only the Autolite decal which identifies the air cleaner assembly and air filter element should be on the side of the air cleaner base.
16) Blue overspray missing on intake manifold.
17) Cork valve cover gaskets?
18) Windscreen wiper motor doesn't appear to be detailed.
19) Dipstick handle wrong colour.
20) Maybe missing cardboard heat riser tube and Wittek No. 34 clamp.
21) Engine assembly date ink stamp missing on front face of driver's side head.
22) Not ordered with rear spoiler.
23) BOSS 351 decal on driver's side valve cover is incorrect.
Did you see the auction for the GG car in QLD? Much nicer
https://collectingcars.com/for-sale...display&utm_campaign=ccapac_brand_unique_cars
I'll answer questions if you like. I'm in Darwin and have a Grabber Yellow B1.