I had the same question ....... once
My Hunter is a 1979 H25. The interior is very similar to that of the Cherubini designed 27s (just not as much of it). I had the same question several years back. For 2 or 3 years I had been using Old English (a furniture oil preservative). Then last winter, I decided to clean all wood surfaces thoroughly, and then varnish. Prior to doing so however, I consulted a number of people concerning what to use and how to use it. Based on what they said (or perhaps it was that I was just plain lazy), I cleaned and refinished all interior wood with a Coconut Oil teak oil (purchased it at Boats US). Worked great, smelled absolutely fabulous, and has held a nice soft shean all summer long (applied in March and now it is October). It holds up well even on steps and walking surfaces. Just do not make the bruising mistake (that I did) of using those surfaces prior to the oil sinking in. As a side bar, the Admiral was really pleased with the results. She then made the comment that, should I have asked her what to use, she would have told me to use a coconut based oil (apparently her parents used this type of oil on their teak furniture). Must be a New Orleans thing.