Yeah, I'd agree, if it were a building that contained 61 and 63, then `61;63` denotes that, but I believe the actual address of the building is `61-63`. Not sure if it's intended as a range per se, but is actually the house number that's in city systems (Here's Boston Assessing, which I'm not sure we can use as a mapping source, because copyright, but I like to use to check some of my assumptions: https://www.cityofboston.gov/assessing/search/?pid=0303752000)

If that's the street number that's on the building when you surveyed, I'd map that outright, rather than trying to determine if it's meant to be a range covering specific numbers.
Per the wiki
> When such a range is officially used for the entire house, this is the preferred method. In this case 10-95 is simply a label like any other. In this and other cases, house numbers officially contain a dash and are not meant to be treated as special.
> Note that in some cases building or building complex has single address such as 3-5 that only looks like a housenumber range. As usual, do not convert such data blindly, without a verification.

This sort of housenumber is actually rather common in the map around Boston, so I don't think it's wrong to maintain the dash if that's what things are signed as: https://overpass-turbo.eu/s/1O1T