Industrial Serger - Stuck Crankshaft / Handwheel / Differential

Hi All.

My wife recently purchased a Wilcox & Gibbs Industrial 5-Thread Serger
(515-4-52).  The handwheel and crankshaft mechanism are completely stuck and
only rotate about 1/8" in either direction.  I got it to work briefly when
we first set it up by strongly turning the handwheel until it rotated, I put
the belt on the handwheel and it worked fine for the evening.  The next
morning it had frozen completely and will not turn regardless of how much
pressure I apply.

Through my investigations, I found that the Differential Feed Shaft and
Lever are stuck as well.

I opened the machine to the best of my ability apart from removing the oil
pan and opening the main body - I put in new oil, and oiled all sections of
the crankshaft, all ball bearings and bushings that are accessible.

I cleaned the needle/looper section extensively looking for anything
blocking these parts and nothing is abnormal.

And after spending about 6 hours trying to get it to work, I put the machine
back together and turned away IN FAILURE!!!

SOOO - if there is anyone out there that can offer any advice - or point me
in the right direction - I would be eternally grateful.

Thank you in advance!

See Alt. Sewing far more active group