With ABC you had two books with all the cities listed in alphabetical order. Under each departure city they then listed destination points; direct flights first then a separate list of connections. OAG published a book for domestic US and a separate book for "everywhere else" and did what I thought of as the opposite of ABC. They had the alphabetical list of cities but they were arrival cities with departure cities listed under each arrival city with directs first then connections.
The disadvantage with each, if you only subscribed to oen, was that to construct you own connections you were hopping about in the books. If you had both you could open ABC at the departure point, OAG at the arrival point and then run through the cities until you found a common point.
IN both cases I believe the connections were sponsored by airlines rather than simply constructed by the publisher.
Both publishers also listed minimum connection times for when you were constructing your own connections.
There were some fares but there were separate books for anything more than a simple round trip published by different organisations. I can picture them in my mind but I can't remember the publishers. They didn't always agree! (Mind you, neither do the computer systems today).
As for ticketing I went from hand writing to the early Travicom system where airlines still provided you with their own tickets so you set the system going, inserted the correct airline ticket into the printer and it (usually) did it's thing. That system had issues with bar codes that the printer didn't always read. Then BA had Travicom install printers where the tickets were on a continuous feed which led to a system where the airline name was left blank and the system printed the airline name and code but you still paid the airlines sperarately then to BSP which is a centralised clearing house - all the money goes to BSP who then dole it out to the carrier named on the ticket (so interline billing still happened). Next we got ATBs, still BSP based and finally e-ticketing. With hand written tickets you occasionally got an article in trade press that some agent had written a hugely complex ticket and there would be a picture of several people very carefully displaying a long daisy chain of tickets. As time went on the ability to squeeze lots of information by writing very small on a paper ticket went away so that we now have a limit of 16 coupons on an e-ticket (or did have when I retired).