I think so, but even the way you tagged it is great… The name alone sort of asks the user to go google it for themselves, and I’ve sometimes done just the name when I’ve been in a hurry. The URLs are preferable because it’ll take the next mapper directly to your source with minimal barriers.
if you wanted to go overboard, you could do:
source=[url to an image of the map or to the info page for the map]
source:name=[name, like you did above]
source:tiles=[url to the xyz tms or wms or wmts server hosting a georeferenced map]
And, the extra super-credit is to link to either wikimedia commons versions of the map (if high res enough) or to an Internet Archive link for the source map. That all said, again, what you’ve done is great.
If I had to choose one of the two links above as a canonical url, I’d go with the first one, as it includes the WMS endpoint on the page.
Thanks for such a thorough follow-up, thank you for using the source tag, and best wishes for your efforts!