you could also check some trucks that have the washer clipped onto the wiper arm, chevy trucks from mid 2000 maybe? some highway trucks also have some interesting stand alone washer nozzles that have adjustable sprayers.
https://www.amazon.ca/Dorman-47191-W.../dp/B00OZSLNXQ
https://www.oerparts.com/product/3718638.html
https://www.camarodepot.ca/exterior/...zles-1967-1969
or maybe something like this without the lights
http://www.autolumination.com/washers.htm
another clip on with possibly more nozzles
https://simple-engineering.com/produ...asher-nozzles/
or some chrome
https://www.musclecarsandclassics.ca...zzle-1963-1967
dunno if you could make something like this work
https://www.musclecarsandclassics.ca...zzle-1953-1962
a little spendy but if you think they would work you know what they came from so could try another source
https://www.musclecarsandclassics.ca...rect-1963-1967
I think with a split window you kinda need one nozzle per side, why I thought the nozzle on the wiper arm might be a good idea. that and you would not need to drill any holes in a large panel in case you really don't like it and have to weld them closed.