I would suggest calling Will Beemer at the Timber Framers Guild office 413-623-9926 and order a copy of the Timber Frame Resource Guide. There are listings for several restoration specialists including Jan Lewandoski who is a Vermonter.

As far as a do-it-yourself guide to barn inspection and conversion, there are none I am aware of. You can do some some related reading.

Robert F. Ensminger's "The Pennsylvania Barn" is a very good book on one of the midwest's most classic barn forms.

Hubert Wilhelm's "Barns of the Midwest" introduces the ethnic origins of the barn builders.

"Barn" by Endersby, Greenwood and Larkin is a beautiful book which includes wonderful photographs of converted barns.

Your best bet to get information first hand would be to attend the TTRAG conference in Stanton Virginia in March. Hugh Wilhelm is one of the speakers and many specialists in historic timber frames will be there. Check the website for details.