I think the GMC chassis is from 1955. So in 1973 when the photo was taken, it was already 18 years old. A well-kept small-town/rural volunteer unit. In 1973 Penryn must have been pretty rural -- even now, it's a small unincorporated community. The Penryn FD has a nice website -- they report having 10 or less calls a month.
Added by Mike Feldman on 28 June 2010.