The hardest part about working on a V1 engine is identifying all the shims as to where they go. They are of varying thickness and need to go back exactly where they came from.
When you split the case be very careful as the shims tend to stick to any boss that they are next to. Then later when you are cleaning the case a shim will fall out and you will say to yourself, "Where the F*** did that come from".
If you can, as you find the shims, measure the thickness and save them individually with a note about where it goes and how thick it is.
The V1 engines are bullet proof once you get it back together.