[Wellcraft19]

When removing starter, careful not to break the snorkels (I broke the mount for one of them). According to dealer, part only available from Japan...

When installing new contacts, make sure they are LEVEL so you'll get the largest possible contact area towards the plunger. It is easy when you tighten the nuts holding the new contacts (as well as when attaching external lugs) to overtighten so you end up with slightly "slanted" contacts.
Check before you put the lid on so you know how much you can/should "wiggle" assembly back in order for it to be "level", and hence provide for largest possible/best contact area .

As you can see from pictures, new contact on one side is slightly narrower than original (this being on a 2kW starter).

Bench test starter before you put it all together. Needless to say, make sure it is properly mounted in vise or other device.