Quite a few of Life-Like's models have their origins in other product lines such as American Train & Track, Penn Line and Varney. The F7 is a former Penn Line model and is fairly easy to find. Check out the following link to the Life-Like section on the HO Scale Trains resource. It contains an excellent summary by equipment type including model origins. Just click on the listings in the left hand column for the information pertaining to that particular model.
http://tycotrain.tripod.com/li...sresource/index.html
Bob