Hi Peter.
That is a nice looking spectroscope
You have the neon calibrated so you can work out the dispersion of the set up and note it. Then go back to your original spectrum and do a one point calibration, entering the dispersion from the neon one. That will show you what emission lines you have.
You'll need to sort out the light ingress though, and your image is very "blocky" which might lead to some resolution issues. What sort of camera are you using Peter?
Stu