I don’t have an Avianca timetable for 1950, but do have for 1949 and 1952.
In 1949, there were no transatlantic services yet, but a twice-weekly DC4 operation to New York and Miami, and some DC4 operated domestic runs on the triangle between Bogota, Barranquilla and Medellin. Three DC4s were required to operate this network, the rest of Avianca’s operations were DC3s, all operated under the Pan Am name.
In 1952 Avianca was already operating L-749 Constellations, delivered the previous year, on its transatlantic schedule, if they had run transatlantic DC4s it must have only been for 1950. This was quite advanced, as on the mid-Atlantic route Iberia, Alitalia and Cubana were all still running DC4s. The schedule was :
Alternate weeks (Fortnightly)
AC 776
Bogota 1000 Tu
Barranquilla 1150/1235
Bermuda 1945/2030
Santa Maria 0635/0720
Lisbon 1235/1420
Madrid 1540/1625
Paris Orly 1905 We
AC777
Paris Orly 1200 Fr
Madrid 1450/1535
Lisbon 1705/1750
Santa Maria 1840/1925
Bermuda 0305/0350
Barranquilla 0900/0945
Bogota 1135 Sa
You will see no reference to Rome or Frankfurt. Avianca was unusual to operate into Paris Orly at the time, most foreign carriers used Le Bourget while Air France concentrated on Orly. It must have been a logistical challenge operating such a long-line route just fortnightly, crews being away from home for an age.
The Constellations operated a thrice-weekly service to New York in 1952 as well, alongside a weekly DC4 operated as a "tourist class" flight. Avianca took delivery of two L-749As in Spring 1951 to operate these services, HK-162 and HK-163. They were not ex-Pan Am but were new aircraft. This pair were supplemented by three L-1049Es in 1954, but in that year HK-163 operating the transatlantic service was lost in an accident in The Azores.