Our old girl had a Bukh DV24, 20 years old and still going strong. Fabulous donk, along with Yanmar I believe they are the only marine diesels that are not simply marinised motor vehicle.
As for parts in the US for some reason I had the feeling that Bukh is sold in the US but not under the Bukh name. Bukh parts are expensive I do readily admit.
Siden blev ikke fundet - BUKH A/S
might be of some help.
If it is a DV24 let me know, I have the manual which I could email to you.