1988, 45’ Californian. Interior woodwork maintenance

Since Navigator is out of business there is no information from them any longer. 1988 I don't know the wood or stains they used. There is a chance that @PacBlue will be able to help answer this question. I am guessing walnut.

I would guess not teak. You could post a pic here and see if some wood guys could identify the grain and color, or you could match it against the pics here: https://www.wood-database.com/wood-finder/?fwp_name=T&fwp_paged=2. Next, from '88 is it varnish or urethane and then color match. If we have some carpenters here you should get answers.

1988 predates the Navigator era, Carver was the caretaker of the brand during that time and moved production out of California toNorth Carolina I believe. When the Californian’s were built by the Marshalls in the state of California, I believe they used a lot of Walnut for their interiors without any stain. I don’t know what wood Carver used when they owned, suspect it may not have changed?

https://atlanticyachtandship.com/californian-yachts-history/

Later in 1998/1999, June Marshall ran a trademark search and found that Carver let the trademark lapse on the Californian and Venetti brands and stole it for a song and a dance. Eventually settled with Carver and quite a few molds like the 45 Californian MY arrived at the Navigator plant in Perris, California only to be cut-up and scrapped to the trash dump. He was only interested in the brand names, not building cockpit/double cabin motor yachts at that time.

http://www.navigatoryachts.com/index.html

Interior wood types are somewhat driven by veneered plywood availability. In general terms, I have seen many interiors that look like a match for teak in color and tone, but are actually cherry. One way to identify cherry. is that it darkens as it ages. If there's a piece of artwork or framed photo that can be removed easily, you can see the contrast. The concealed wood will be lighter, and that even happens below decks. Teak, on the other hand, becomes lighter, and the concealed parts are darker. Honduran mahogany has been virtually unobtainable in volume for many years. Philippine mahogany is very unlike Honduran mahogany or teak in appearance,and is too soft and splintery to be a viable commercially used lumber.
From patching interior "Varnish", I've learned a few things.
Almost all interior finish is satin, but build coats should be gloss, and the final two coats should be satin. Otherwise, you'll end up with a conspicuous "bruise".
Interior finish mellows and develops a "honey" warmth, even if it starts out as a two part polyurethane "clear". Schooner Gold is my favorite for build coats.
Inexpensive artist sable 1/2" brushes make all the difference in finish quality. Really, REALLY, worth it! Besides, you look and feel cool using them
When you get to the final finish, wet sand with 1000 grit, or so, then polish with a scratch remover. I use Novus plastic polishes. It's helpful to think of cured finishes as hard plastics and treat them accordingly. Videos on plastic headlight restoration are a real confidence builder. The kits are handy for repairs, too. I've polished out scratches on varnish that well-meaning people have inflicted on gloss table-tops with scotch-brite sponges. Get out the buffer to finish!
There's no such thing as an invisible repair to the person doing it.

Roger Hansen probably sold more Californian Motoryachts on the East Coast than an6 other single location, they should know the boat well and are a good Florida resource:

https://rogerhansenyachts.com/

As stated above, all the wood walls/bulkheads and cabinet faces you see are usually a veneer over plywood with exception of some corner posts, rails and solid door frames.

Finishes were usually commercially sourced and not the name brands like you would see on the shelves at West Marine. And in an emissions sensitive area like California, they turned to water based finishes a long time ago when you are building anything of volume.