I can....... but it's in east London, so not a lot of help as you're in Cheltenham! I know a technique that I've used on my Daf 33, which also solid centre 3 stud wheels though; try this:
1/ As the Renault 4 is front wheel drive, this might involve quite a bit of jacking up and lowering.......
2/ Put the wheel you wish to balance on the rear axle, as this will prevent any "drag" from the gears affecting anything.
3/ Slacken off the brakes completely & remove any weights from the wheel rims.
4/ Spin the wheel as hard as you can, listen to confirm the brakes are NOT touching in any way and note the position of the wheel when it stops spinning. If the wheel slowly rotates the other way when it comes to rest, it might need balancing, since this suggests a heavier part at the 6 o'clock position......
5/ Spin the wheel a number of times and note the position of the wheel when it stops each time. If the positions are randomly spread, you're probably O.K., but if the wheel settles with one area at 6 o'clock, the weight needs to be placed opposite, at 12 o'clock.
6/ It's a long process, but it does work.....
7/ Don't forget to put all the wheels back on the axles and tighten the nuts to the appropriate torque settings!
