Univac panel and mystery TTL chips

[J. Peterson]

Hi,

I have a control panel from a Univac mainframe that I hope to re-animate 
someday.  Unfortunately I know very little about Univac mainframes.

First I'll go for broke: does anybody recognize this unit and have 
schematics for it?

http://www.saccade.com/writing/projects/UnivacPanel/UnivacPanel.html

No?  OK, time for plan B, reverse engineering it.  Most of the chips on the 
panel are straightforward 74xxx TTL, however, a number of them appear to 
have a seven digit part number instead of a regular 74xxx stamp. Is there a 
translation guide between this seven digit number and regular 74xxx 
numbers?  Most of the 74xxx parts on the board also have these seven digit 
numbers.

Any tips on how to guess the actual function would be most appreciated.

Thanks,
John Peterson
www.saccade.com