Hi Nell - Congratulations on taking the endeavor to restore the Flathead. I am on the tail-end of a similar adventure.
Besides this board, where there have been invaluable tips, suggestions, admonishments and warnings, you will find considerable information at the ModifiedCadillac board, and a wealth of documents, along with an extensive service manual for the tank engines (Flatheads) which goes into considerable detail about the engine - Click on the 1944 link. Oh, and the gentlemen on that forum will have good information for you as well.
http://www.modifiedcadillac.org/documents/1940s/Another great source is a series of articles written by Walt Brewer and published in the Self-Starter. This eight part series is hosted on the Rocky Mountain Region website, and can be found on-line at :
http://www.rmrclc.com/waltsWorkBench.htmlScroll thru and locate the Restoring Your Flathead articles.
For parts - I think highly of Terrill Machine in Deleon, Texas - they have been doing this awhile, and have an excellent reputation. Otto hosts a list of most of the more popular vendors that can supply you with just about anything you need.
And keep us all posted. There are several Flathead gurus here on the board, and a wealth of general information that applies to most any engine.