I believe the early and late are interchangeable too. At one stage I recall being told the torque rods had been replaced in my 88 240 with early model ones as they were stronger, or better bushes, or something.
A member here had some adjustable ones installed recently, he may be able to assist with where to find them. He may also be able to assist with correct adjustment.
iPd link
https://www.ipdusa.com/products/4918/109772-adjustable-torque-rods-200-series-models
Second hand is also an option. Over here (Melbourne) there are two popular 'classic' (or 'old', your call) Volvo workshops and they both post to almost anywhere. Berry Motor Group in Mitcham and Voldat in Morrabbin. I am confident they will both have plenty of stock of these.
I think I have some bushes on the shelf too which will not be used as I will be using the iPd poly units rather than plan A which was to replace the bushes in the original arms.
Recommendation is to use the iPd ones. They are on special at he moment, $50 off!