I looked into the Bangin' Headlights that people rave about, excellent light and look original, but, at around $250 they can shove that......I ran Narva relays on new sealed beams, made a heap of difference. 

I may have missed it, but how old are the tyres? or more importantly how long as it been parked in one spot on them?
My van had out of balance type vibration when i got it, tyres were flat spotted from being parked years,(never came good from driving) and I'm betting the same will be the case again for My gemini and van again because they've basically not moved for 5yrs (sadly tyres are almost new wear wise)
I've got ones that haven't been on the car that i'm hoping will be fine on another set of wheels for the gemini. 

is it worth trying 2 new tyres? that's My short version of the above. 

 

I got ya covered

I haven’t measured them on a dial indicator but yes of the 12 wheels (3 full sets) i have for the car, all of them are visibly not dead straight. I picked out the best two, one of which is near perfect then had them balanced properly. It has not changed how violent the shudder is at highway speeds. 
hence im looking at the alignment again. 
  If you haven’t followed the build, the car is very adjustable in the front. With caster and camber tops, adjustable sway bar, and adjustable shocks all round. 
  it will also come and go when cornering at speed, which to me suggests the toe angle or akermans angle is getting messed up under certain conditions. 
  If this does not solve the issue, or get it to a bearable point, ill consider new hubs, but i have also priced up a full set of new reproduction wheels. Both the 13x6 lotus steels, and the RS 4 spokes. A new set of the RS 4 spokes landed is similar to getting my original Ford RS4s fully restored. Being alloy, they are easier to repair than the steel wheels. 

I have had the same vibration previously on my XG , it was caused by a slightly buckled rim after hitting a pothole. Perhaps measure the rim runout with a dial indicator ?

not sure on the aftermarket lights, assume they'd be fine if they had an ADR on them, but those LED globe replacements are not legal.    are your lights sealed beam? if so they'd be better replaced with NARVA or HELLA globe type lights (whatever size they are? 7"? ) and just Narva etc 60/55 globes would be better than sealed beams by far (did this with my gemini in rectangle Narva and Hella on 2 different cars)

the auto elec told me the sealed beam lights would equate to 80w and run through the switch without a relay, so going 60/55 in modern lights wouldn't need a relay added (confirmed with my cars) and the difference is double at minimum clean light with focused beams where they should be. 

 

Way cool.!  Have to grab that one. Cheers mate  

G'day again folks. Apologies if this is posted in the wrong area. I wasn't sure if it's body and exterior, or electrics?    I mentioned in passing to my mate who is helping me out with the XC, that in the future I wouldn't mind looking at getting the LED replica lights for the Falcon just to see better than with the old 70s antiques.    He said that he had a feeling that they're not legal in Vic for cars of that age. Does anyone know for sure if they're road legal under Vicroads legislation?   Thank you. 

Yeah ive been through all that. 
  the 15s on the front now have centering rings. The others don’t need rings 

Do the rims fit snug onto the hubs?  Or is there as gap between the hub and the rim?   If they don't fit snug, you'll never get rid of the vibration.  You'll need a set of locating rings (not spacers) to fix it.