It's an easy operation to pull the bottom plate off and clean the old grease out of the chain tracks and lubricate that area appropriately, it made a large difference in the winding feel of both my VT and VT Deluxe. No special tools required, aside from a well fitting flat blade screwdriver.
Totally agree,
Some years ago I gave a (just bought) Vt to an "expert" Leica repairer at a major Melbourne shop to fix the slow speeds.
Yes,he fixed the slow speeds, but I could no longer use the trigger.
After being returned twice, the trigger was still playing up. Due to frustration, I just put the camera on one side. (I could rationalise this because I had paid a very good price for it plus the filters, hoods, lenses,etc.
A few years later I decided to see if I could get it working.
Removed baseplate, carefully cleaned old grease from the gears and chain (very careful and miniscule use of electronic cleaning solvent helped), then a tiny amount of sewing machine oil where needed.
10 years later my Vt is still working properly.
It's a great camera, but you've got to be careful when taking it internationally; I've found the trigger must be explained; etc.;etc.
😱