Why I ask is that I wound up in 1972 having to use a line following digitizer build Metro area maps for Seattle and Atlanta at their 1970 Census of Population status and also to digitize both areas' electoral precincts as they were when each of the two cities voted on whether or not to have a bond issue to pay the local portion of funding to build a rapid rail system.  Seattle turned theirs down twice and Atlanta turned theirs down the first time but passed it the second time.  If you've been in Atlanta in the past 35+ years, you'll note that MARTA in Atlanta has been running since the 1970s while Seattle finally started building theirs only between 5 and 10 years ago as of today and started with moving traffic out of SEA-TAC instead of out of downtown.

If he's able to put something together to be able to digitize the maps himself, I'd also suggest that he contribute a set of the data files for the time periods he's interested in so that the next guy (and his librarian) don't have to go through this process.

If it would help, I believe I still have a copy of the instructions I worked out for the people that helped me do the digitizing.

The worst problem I had was figuring out the basis for the outlines of the maps.  Mainly this was because I was limited in the size of the matrix I could use to do the statistical analyses to figure out what I was looking at socio-economically.  I finally wound up using census tracts of which each city had about 250 and aggregating the precincts to the corresponding census tracts.

Hope this helps.