A 61.5 current Homer is a big-big bike. Like an XXL. A 56cm 1970s Paramount is barely a medium-sized bike. In Stack and Reach terms, a 61.5 Homer has Stack of 671mm and I'd wager a 56cm 1970s Paramount is around 550mm, so you'd need a stem that is approximately 12cm TALLER on the Paramount to get the bars in the same neighborhood. The reach is probably going to be closer but still it's probably between 30-50mm shorter on the Paramount, so your stem that is 12cm taller would also need an extension that's up to 5cm longer. Generally speaking, that would be a bizarre looking stem and the bike will likely handle pretty oddly.
If the 61.5cm Homer is remotely "correct", that Paramount is WAY too small. Like, not even close. If you fit a 54.5cm A. Homer Hilsen, then making a 56cm Paramount fit would be pretty straightforward. Take some photos of the bikes next to each other. Take some objective measurements to see for yourself, or try it out if you are eager for the experiment.
Bill Lindsay
El Cerrito, CA