Hi Rick,
You are doing far too much work here. The IC-7300 is not a clone mode radio, it's a live mode radio. As Dan mentioned, you should be extending the same base class as other Icom live mode radios, in icomciv.py. Looking at the IC-7300 Full Manual, I see that the IC-7300 behaves in exactly the same way as the Icom live mode radios that are already supported. Thus you'll only need to add a few definitions to icomciv.py in order to have IC-7300 support.
Looking through the existing IC-7200 code should help you to understand what needs to be done. Since I'm the one most recently in that module, adding IC-910H, I'd be happy to help if you have questions about how the icomciv.py code works. It took me a while to figure it out, but it's actually quite straightforward.
Martin.
KD6YAM