Mystery 1970 core board

[Jules Richardson via cctalk]

Hopefully collective wisdom can help on this one - does anyone have a clue 
what system this core board was from: 
http://www.classiccmp.org/acornia/tmp/coresmall.jpg

The curved edge connectors (presumably to make board insertion easier) are 
quite distinctive, plus the way the power's fed in via an edge connector on 
the "far" side of the board. What's interesting to me is the core ring 
size; the TTL ICs on the board have 1970 date codes, but I didn't think 
that the rings got quite that small until right at the end of core's era, 
more toward the end of the decade.

It seems to be 8 blocks of 64x64, i.e. 4KB. p/n on the main board of 
2001000755, and just hidden from view under the core daughterboard is a 
logo that says "LEC", which I suppose might be meaningful.

There's a bigger (2181x1863) image as "coreboard.jpg" in the same dir if 
more detail helps (I doubt it), but it's 2.4MB so maybe save Jay's 
bandwidth by only looking at that one if you absolutely have to :-)

thanks,

Jules