I think the shocks I have are 1975 or 1976 for SLR5000 fronts, will check when I get home. They are in blue and white GMH boxes.
When you look at the formula it is pretty close to Woodsman Green in tinters and quantities. I reckon you'd go close to using Woodsman Green and no-one would notice. By chance I have one of the original front guards in my shed off my remaining HK Monaro which was Woodsman Green. When I put the 1974 shocks next to the 1968 paint it is pretty hard to pick the difference, sprayed side by side using fresh paint it'd probably look like an original Elizabeth build metallic Holden where the front panels always looked different to the firewall back as they were painted in separate locations at different times. But on shocks under a car, you'd not notice it.
What was interesting with the shocks I have for my Premier. They are not the same as a run of the mill HJ Holden being a 5.0L auto, air and steer car. They came from a dude resto-modding a tired but very original HJ Premier of the same spec but from late in 1975 whereas mine is late 1974. When the shocks arrived, not only do all four have the broadcast sheet code stickers, they are all made in and around September 1974. So it's clear that GMH must have obtained shocks in batches on an economy of scale basis, given those on this spec Premier would be low volume they must have had a minimum quantity, and they were still using them over 12 months later.
Do they re chrome the shafts Col?
Teh, place I spoke to Laurie use new Monroe internals. Cut the end off the old shocks and put all the new internals in with the valving as per the original spec on the old outer tube.