Check that it's a wool pile Ax. Especially during the 80's, acrylic was a popular fibre in axminsters. Not many around now but occasionally you can be caught out.
Being an older carpet, vac it really well. North/South, East/West. Perhaps repeat. Time spent now will be rewarded later.
Presuming fitting and dyes are OK, follow Russells advice on chemistry or perhaps use a Woolsafe detergent rinse, but acid rinse is fine. Even if fibre is acrylic, stay Woolsafe because of the jute in the weave. Acrylic responds well to heat.
Acrylic Axminsters were the Belgian Wilton of their day, although not as moisture sensitive. I would still rinse/extract these but with care.
Safe and happy cleaning

Ken