I recently stumbled upon a couple of websites that would seem relevant and of interest. The first is "Spectroscopy Europe". Back issues of the magazine can be accessed.
Next is a website called "all radioactive". There may be forum users contributing to this information - I was looking for spectra for La-138. Links follow -
https://www.spectroscopyeurope.com/
https://allradioactive.com/radioactive-lanthanum-138/
