Not being familiar with DD, I did a search on his name. Numerous posts written by him on Rypn.org came up on steam locomotive topics. From those, it seems rather obvious that his primary interest in rail preservation is steam locomotives, and not diesels. The post above by BW of Dennis halting restoration of the F7 midway through the job in favor of steam projects now makes more sense.

Makes me very sad to read all these painful stories about CSRM mis-steps.