They show faintly in SkySafari if you set the MilkyWay layer to h-alpha.
This is precisely zero help in ID'ing nebula, but does suggest profitable areas to sweep with your scope. If you find a gem (like this case) then you can turn to other sources for the ID.
The easiest is Bracken's Astrophotography Sky Atlas. As good as that one is, it concentrates on the most photogenic.
Next step is the brute force method. Take the Sharpless list, which is systematic. So, constellations tend to fall into sections on the list. For example, Orion entries are #252 thru about #280.
Take your sketch and go to web sites like these:
And start looking at the mug shots until you find your perp.
Edited by Jeff Morgan, 13 January 2021 - 02:59 PM.