So if timber is an agricultural activity and a Matador timber tractor is an Agricultural Machine and you can meet the regulations/conditions for towing agricultural trailers and intend to pull a laden pole trailer - then I imagine a Matador could and should be taxed AGRICULTURAL for this type of work (you cannot tow laden trailer under HISTORIC tax).
If you are using it for off-road timber work only and just move from site to site on the highway,as has been said above it can be taxed HISTORIC.
Isn't what the V5 show under TAXATION CLASS the key to how you can use it?
A lot of mvs are still described on V5 as being Agricultural Machine/Tractor etc - yet shown on V5 as beng taxation class HISTORIC - because before the days of HISTORIC tax class it was often the only realistic way to register them. It doesn't really matter what the description of vehicle is, because as long as the Taxation class is shown as HISTORIC it can be used for pyurposes allowed by that taxation class (Locomotives etc currently excepted I guess).
Tmes have moved on and, as has been said, HISTORIC is the simplest legitimate way to go for recreational use. However frustrating it might be for certain types of vehicle, we are still really lucky to be able to be able to tax most of our old mvs this way :-)
If you are lucky enough to own a big estate with a sawmill as well as the Matador (if you could even be more lucky than just owning a Matador ) you can go AGRICULTURAL and have the best of both worlds!
Is there (technically) a problem using a pre-1960 vehicle which meets the HISTORIC criteria for recreational use, even if it is taxed as AGRICULTURAL MACHINE?
P.S. How's the Albion restoration progressing?