Aye, three track aspect of the ship that clears a mark from any damaged ship rating when we drop anchor. Given it's a three track and the ship image shows three bunks for the undercrew, I figured there's three of them.
A few idea-things I came up with that we could go for a basis of all or some of the engies and keep a spectral theme:
- A literal spirit of the ship taken form (ships have souls and the Slipfang is able to create one or more sentient avatars who repair herself)
- A small ironbound or ektus made of living wood (something akin to a dryad)
- A group of squirrels governed by a slightly spectral queen squirrel and are at odds with the spectral slinks (could also just be a single engineer being a single clever squirrel or a group of squirrels in a trenchcoat)
Them having a spiritual element can be why they didn't get too involved with Pieter II's building (too much of a risk being nabbed by the other spirits.)
Or we can just have regular people of varied backgrounds and races who joined the ship to gain skills and one day become true rattlehands/engies.