I bought Don Casey's Complete Illustrated Sailboat Maintenance Manual. It has Troubleshooting Marine Diesel Engines by Peter Compton as part of the book. I also bought Seloc's Yanmar Inboards as I have a 2GM20F.
Would Calder's book be of any value to me?
I have Casey's Electrics Simplified, and Sailboat Refinishing, as well as Compton's Troubleshooting Marine Diesels. I now find Calder's book to be SO comprehensive. There are 17 chapters, dozens of troubleshooting charts, dozens of Tables; it's a really big book. Don't fall asleep reading it or you'll break your nose! I think the sub-head to the book captures the difference: "How to Maintain, Repair, and Improve Your Boat's Essential Systems." The Improve part is catered to with lots of planning examples. So it goes quite a bit further than the other repair books. My friend has been traveling the world for 3 years in his Catana 47 and he recommended it to me as his one essential manual. This, and the engine manual, are all you'd probably need.