..............As the co-pilot on my first airline job, I did the fuel plan sheet for approx 1 hour segments, followed by a seperate airways/ all waypoint portion - all from blank pro-formers. Then filled in multi-addressed official ATC plan forms at appropriate office - multiple copies each over carbon in places like India. Attended compulsory ATC briefings, which in Oz even included shipping movements and around a kg bundle of briefing sheets. Manual loadsheet in cockpit, but maybe Capt would do the trim using a flat circular cardboard "computor" with "windows" cut into it. I also did most of the accounts, since we only had two non-tech office staff. This was props, but it was the move onto longhaul turboprops ( Britannias ) and working forwards or backwards through those fold-out performance graphs that it all got a bit much, so in the two companies I worked for, the Captain mostly did the loadsheet, and the flat-table equiped Navigators, who always seemed to me better and quicker at sums than most of the pilots, did the performance on the long tricky sectors when they were most likely to be around. Having said that, a lot of pilots had nav licences as well, (as with BOAC and others during the 1950/1960's) and at one point we operated briefly with Americans who flew in all seats. One, I remember (Airlift) bid or was rostered as a Nav on the DC7c, F/O or Eng on DC8 or 707, and Capt. on 727.
......Back to the loadsheet thing and forward a few years to the 747-400. A score of backroom friends in load control start a loading plan 24 hours ahead of sked. Now we get a computor print out for signature shortly before push back; carefully select the right buttons, and a shortwhile later whilst taxiing out, the Acars will squirt out a printed update. Seemed to make life simple. However, after about five years of retirement in a different regime, I returned for a few months as an F/O on a 747 classic. Suddenly we're back to doing the load sheet and trim on your knee when the figures arrive not so long before pushback. I had to think about this, but the big difference is that now we have pocket calculators which weren't around before. It was pax, not main deck cargo, but it was back to rule of thumb initial load plan, plus scribbled cribs in the little black book plus basic weight/mass and index from the flight manual or tech log.........a bit rushed perhaps, but as far as I know, no incidents that I heard of.