Just got off the telephone to the developer and we have a new minor release completed already (7.31) based on feedback from Classic users so we will now test it and get it released shortly if it passes the tests.
Judge by results:
PPaint 7.1 source code modernised DONE!
PPaint 7.2 developed DONE!
PPaint 7.3 developed DONE!
PPaint 7.31 (In Progress)
We are now in the process of moving to 7.5 and then onwards.