Anyone know where i can find this - there was one under "Legal Stuff" on the old ARF but I cant seem to find it here - thot maybe Bigger hammer but I couldnt find it there either - any ideas??

FYI here is some useful info

Also note that simply because a given lower receiver has a "pre-ban" serial
number does not necessarily mean that the firearm was assembled prior to the
ban, only that the receiver was manufactured before the effective date of
the ban. In order for an assault weapon to be "grandfathered", it must have
been configured as an assault weapon prior to the ban (the effective date of
the ban was September 13, 1994.) If a stripped lower receiver was in a dealer's
bound book at the time the ban took effect, and it is later discovered in an
assault weapon configuration, it could be rather easily ascertained that it
is not a grandfathered firearm. Receivers in private hands on the day of
the ban are a little more ambiguous as who is to say if it was or was not in
an assault weapon configuration on the date of the ban, and then later stripped?
As always, buyer beware.

http://home1.gte.net/bblakley/ban/

ArmaLite's official
"generic" position on pre/post status of receivers they've made is:

1.Almost all Eagle Arms rifles bearing the notation "Eagle Arms Div ArmaLite"
  are post-ban rifles.  The only exception will be on serial numbers under
  30,000.  Receivers with pre-ban serial numbers marked with the ArmaLite name
  are new receivers produced to repair legitimate pre-ban rifles.
2.Many Eagle Arms lower receivers were sold to customers and assembled outside
  the factory.  ArmaLite has no way of knowing which of these arms were
  legitimately assembled into "pre-ban" rifles before the Crime Bill went into
  effect.  
3.ArmaLite's history specialist will conduct research into the
  production history of a given serial number and provide a letter attesting
  to its factory designation and shipping date.  The research will be
  conducted at a cost of $25.00 per firearm.  The customer name CANNOT be
  provided due to privacy constraints.