I've been looking for one of those for years. The one I used to use at a local gas station way back when was a Hunter. Big, saucer-shaped thing that clamped into the rim from the outside, and it had 4 or 5 or 6 little wheels on a shaft that stuck straight outward from the center. You get the wheel spinning (I usually just used one of the rear positions and spun it with the engine) and as it was spinning you twiddled those little wheels on the shaft and you could feel it getting smoother and smoother until it was vibration free. Took maybe a minute if you were good.
Then, you stopped the wheel, read the weight numbers in the windows of the saucer-balancer-thingie and added the weight it said at the arrows it indicated to the rim. Tap (or glue) them on and move to the next wheel. I could do all four in less than an hour including moving them around.
When I had my first Dune Buggy, the rear rims were two stock VW rims on each side, welded together side-by-side at the inner rim - kind of like a poor man's Dualie buggy. I did that to fit a single 285X16 tire on each side. The ONLY way I could balance those was while they were on the car.
So, Mr. Grey, either find one of those somewhere local (trust me, there aren't many around, these days) or try getting them road-force balanced or live with it, but I would start by having someone first check the rims for wobble-trueness and roundness and then go with a new (and different manufacturer) set of tires. I started out with a set of Continentals that each took, on average, (18) 1/4 oz weights per wheel! Put up with that for a long time and finally went with a set of Michelins which took maybe 2 or 3 weights each. Still had a very slight tremor at 65, but WAY less than the earlier tires.