Although DW case kits are made to fit Valjoux calibres, they rarely fit without some amount of grinding/polishing. Because there is little to no consistency between 1 case & the next, it is impossible to predict how much work will be required until you gather all of the pieces together & see what fits & what does not. If you prepare for the worst (everything must be modded to make things fit together), then you will not be (too) surprised when you run into problems. Of the several I have constructed, only 1 went together with a minimum of fuss. If you are good, talented, have the patience of Job & very, very lucky, you may end up with something that looks like 1 of these
There are a number of tutorials, reviews & journal/logs that describe the process, required tools/parts & potential problems when constructing DWs. Please use the Search to find them & then read before proceeding.