ABA block and crank ?'s

[deadbolt at mindspring.com (S. Coleman)]

First thing up.... what is the deal with this paint/coating they used on
these Mexican made blocks... it isn't even close to the same stuff they used
on the German ones.  Plus the blocks seem to rust up more on the outside
than the German blocks... just wondering if anyone else has noticed that.
Secondly,... I have three ABA cranks sitting here, (what I say are the early
ABA cranks that are forged)  and on two of them, the area around the rod
journals are "heat" marked.   Meaning that they have some blue-ish marks on
them like they were heat treated maybe.....  any ideas.   (I also wonder if
they were "heated" while the car was running?)  Also,... I have the crank
out of another vw here, (2.0) and there are no heat marks on it.... wonder
why?     Lastly, can someone confirm what the difference in looks (as in
what to look for) is between a forged crank and a cast crank.  My boss and I
are arguing that fact as well as why one is stronger than the other.
Many thanks,
Chris
'88 16v Rocco
'78 8v Rocco
'80 Caddy
'92 SLC
'02 337 1.8T
'00 GTI VR6
'97 Golf GL