Interesting that it is a Portacatena equipped frame. That circa 1978-1983 timeline puts it right during the era when three famous framebuilders were working for the Fraysse family at Paris-Sport, who reportedly produced these frames. Per his blog, Dave Moulton started there in 1979, remaining for 1-1/2 years. Per a 2005 obituary written by his grandson, Francisco Cuevas started at Paris-Sport in 1977 before setting up his own shop, with his son, in 1984. That start date is corroborated in a 1984 Bicycling magazine article that goes on to state that Cuevas did a six week stint with Giuseppe Limongi two years later (i.e. circa 1979) that rekindled his frame building interest. Limongi was another known Paris-Sport employee. Moulton appears to be quite amenable to answering questions, so perhaps you could question him directly regarding the bicycle.