Just to throw this out there I have recently acquired a 54 Lima that was set on a pair of tracks from a 104 Northwest. Several descendants of the men that ran the machine are still alive and assisting with the extraction and they tell me it was a shovel front machine that was converted to a heel boom for loading logs and the track frame was to narrow and to short so they stuck the upper on an old northwest lower and were in business, really nice installation to say the least I will post a few pictures soon.