Hokie, yes, there was a MARC AEM-7 in the yard that day. IIRC, this is around the time they tried to start to re-furb the motors but had major mechanical issues that are just now beginning to be worked out.
Wow, a 6 year refurb. 4901 and 4902 are back in service within the last month, and I've seen 4900 once running in testing (it's subsequently disappeared, so I suspect that it's having issues). Thanks for pinning down a start date for me. You don't happen to have any pictures of the MARC AEM-7's from that trip that you can share, do you?