You have my attention 

I don't remember any NIB EMs. I'm not that old.. 

Last year, I did a prtial restore on a Drop A Card and the owner (Slammer) wanted the front section completely rebuilt. So I ordered an entire front door. It arrived with a chrome finish. It is the same part number as a Pro Football.

So the front door to a 70's GTB EM is in fact chrome

Legs are 31 inch chrome

Side rails - need to get back to you on that - but my Jacks Open EM were defintely grained. I'll check with one of my Pro Footballs tomorrow. I expect they are grained stainless steel.

Lockdown bar is definitely grained. THe siderails "should" be the same.

Bally EMs and SS had grained side rails, door and lock down bars.

Hope that helps.