[v8volvo]

In Europe especially it should be easy to find a shim set somewhere. Any garage that works on older VWs and Audis ought to have a set. Maybe you can find a place where you can leave a deposit with them, and borrow or rent their set. It is not that difficult to do it as you describe, measuring the clearance exactly then figuring out what shims you need to get in order to set them all to spec, but it is much quicker and easier if you have a whole set with an assortment of sizes right there with you. Otherwise there is a long time period between when you take it apart and when it is done, or you have to take it apart twice.

You also need the tappet depressor tool (one for an Audi 5cyl, NOT for a 4cyl Rabbit/Jetta/Golf VW engine - they are different), and the shim pliers for removing the shims.

Remember that it is easiest to measure valve clearance for a given cylinder with that cylinder at TDC, but if you need to adjust any, then you have to rotate the engine a little ways in order to lower that piston so that the tappet can be depressed without the valve getting stopped by the piston being in the way. Have to be a little ways before or after TDC for easy shim replacement.

Last tip -- I always prefer to do valve adjustments with the engine completely cold. There are specs for both a cold engine and a warm engine, but how do you know what is "warm" -- and also if you start with a warm engine, then by the time you are halfway through the job the engine has cooled a bit and you don't know if all your measurements are the same. Easiest to work on it cold, so everything stays at a constant temp. Clearance spec for a cold engine is .15-.25mm for intake valves, .35-.45mm for exhaust. D24 firing order is 1-5-3-6-2-4, you can adjust in that order. First three cylinders are exhausts in front then intakes in back, then for the rear three, it's the other way around.