The details of all of the ADR's can be found
on the DOTARS website, because they are superseeded by the third editions we can view/download them for free.
26, 27, 27a, 27b & 27c are all Emission Controls
The compliance plate from my March 1976 ute has
1-Reversing Signal Lamps
2-Door Latches And Hinges
3-Seat Anchorages For Motor Vehicles
4c-Seat Belts
5b-Seat Belt Anchorages
6-Direction Turn Signal Lamps
7-Hydraulic Brake Hoses
8-Safety Glass
10b-Steering Columns
11-Internal Sun Visors
12-Glare Reduction In Field Of View
14-Rear Vision Mirrors
15-Demisting Of Windscreens
16-Windscreen Wipers And Washers
18-Location And Visibility Of Instruments
20-Safety Rims
21-Instrument Panels
22a-Head Restraints
25-Anti-Theft Locks
28-Motor Vehicle Noise
So, unless they forgot to put a number on my plate it didnt have to comply with any emissions controls only Motor Vehicle Noise (28). Also the first vehicle emission ADR was released on 1 Jan 1972, so again I'm sure that you wont have to worry about emissions.
I will put all this up in the wiki under ADR's when I get a chance as I'm going threw all this with my ute and it has a heap more numbers including 27c (DAM IT)...
EDIT: interestingly my 1985 ute doesnt need reversing lights... lol
This is that list for July 1985 ute: 2-3-4c-5b-6-7-8-10b-11-12-14-15-16-18a-20-21-22a-24-25a-27c-28a-35a