I'm a bit late to this thread but ... I replaced some Weinmann sidepulls with some modern dual pivots with no problem. It took some faffing around to make sure I had the right drop - I was a bit unsure what exactly 2 points I needed to measure between. And some searching to get nut fit rather than recessed bolt brakes. The end result? I don't know that the braking efficiency was noticeably different but the old ones were a bit knackered, kept sticking, and were the very devil to get centred right, and the new ones were much better in that respect.
Actually if I'd just taken the old ones off, disassembled them, cleaned off corrosion from the main bolt, greased and reassembled them (which I later did, and re-homed them) then that would possibly have had a similar effect.
If your old tourer has steel rims then I think that will be the key difference between it and other bikes. My memory of brakes on steel rims is that they were really just gentle speed modulators