Mike,
It's not clear if the parts you need are missing or just need refurbishment. I've looked at the tag on the servo on my Britannia which indicates it's a Type 8 4258 Lockheed. Other numbers on the tag: 230; 13?; L20L.
The main tail lights look like Scimitar. Not sure about the fog/reversing.
The shocks I have fitted are Spax Gas Adjustable & stamped 713 EP. Last time I bought shocks for my 411, I bought them (Konis) from Demon Tweeks.
This link may help
J & L Spares, classic car parts suppliers, contact page
Regards
Ian