Sorry Mate, been away for a couple of days, mostly on the road, and NO Net access!
With your 2 bases above, i am unsure the exact meaning of the casting mark, however i also not the extra post on the left side of the base with the I, which is witch, is the I from the first on, or is it the one i gave you.
I picked up another VC-160 today, its a MKI, no starter though (somone has put a pulley on this one) i am going to use it for parts to tidy up my other one, then convert it to a MKII, so if i have the head free (the no-deco type) at the end, i will let you know, depends of the state of the head when i pull it all apart.