If s1b files are truly “just csv files” just copy one to another location and rename it to Mikesfiles.csv etc. then look at it with a txt editor or use excel to examine the file. If so then simply rename the other old csv file to *.s1b.
I don’t know if sdruno allows combining lists with what you already have or whether you need to do that yourself outside of sdruno. If it is just a csv file then it would be a simple matter to do it yourself outside of sdruno.
If you have excel or the free openoffice version it will be very easy to edit and save that file. I opened Mikes s1b file with open office calcualtor (does excel functions) and it was very readable/editable so that should be a good way to make changes outside of uno. If I were you I’d make a slight change with excel, save as csv file rename to s1b file then see if uno likes it.
I’m not running uno yet. I like HDSDR, I like the way you can change the main spectrum and waterfall windows with mouse grabs/drops. You don’t have to make those adjustments in a separate window.