Classic rally eligibility

[Duke Caboom]

Hi, I have completed in several HRCR events but not for the past 6 or 7 years. I was interested in this rule (below) from the HRCR Clubman's regs. Does it mean you could run a car from, say, 1986, as long as it is to the same spec as a 1985 car? How about a 1983 car which is the same spec as a 1980 car. Could it run in category 3?
Thanks

Competitors’ attention is drawn to MUK item
R19.1.Historic Road Rally Cars are categorised in the following periods (see below). A
car will be dated by the specification presented and not necessarily by the date of build or registration.

Typical examples are shown below
Category 1
(to 31/12/1967)
Category 2
(1968-74)
Category 3
(1975-81)
Category 4
(1982-85)

[Duke Caboom]

Great. Thanks. A logical rule.

[Duke Caboom]

So I now see that there is an up to '90 category, which means, presumably, that some pretty recent cars are eligible. Mk1 MX5, for example, introduced in '89