Your bike is precisely the mirror image of my 1962 Bianchi Corsa, whose Universal sidepulls were the mirror image of your Weinmann/Diacompes, and whose rear cable guides were brazed onto the lower left side of the top tube. It came with same-side cabling, exactly the mirror image of what you show. Schwinns were set up more like your bike, with left front / right rear and Weinmann-style sidepulls.
I guess I don't see a problem. Use longer cables and cross them over, as is common practice today, or just keep them as-is, depending on your own preference for brake parity.
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069