Neil:
You should only be using the word "restoration" if you have photos or plans of the course that you are trying to replicate. If you have photos, it doesn't matter whether you know who the architect was or not ... you are restoring his work even if you don't know who he is. FWIW, I feel much better restoring things based on photos than based on plans, because my own courses are never built strictly to the plans, and in fact the changes from the plans are probably the things that are make the course a unique part of my work.
There's nothing wrong with doing a renovation using a general "turn of the century" style, if that's the way your club wants to go. Just bear in mind that would mean vastly different things to different people, and that you will need to be confident of what it means to the shaper or contractor who's actually going to do the work.