In my post in the Suggestions section of the forum, called “Making it easier to use MacDraft Pro”, I also ask about mouse capabilities for us oldies, and get some replies.
Am also 78. I'm using a wired Kensington Expert Mouse (K64325) w/Catalina, and TrackBallWorks v 1.5.0. It works quite well with MDPro. (54mm+/- ball). Have been using this type of mouse for 10-12 years, and am very used to it. Scroll wheel alone does vertical scroll. And with + Shift scroll is horizontal. However, I still have to select the magnifying tool and use left click with either OPTION or COMMAND to achieve zoom function, and then, to get back to scroll, select pointer tool.
I've gotten used to using a couple of the many single-letter keyboard shortcuts available for the tools. Touch the Z key to get the zoom tool, for example, or T for the text insertion tool. And then use the Esc key to return to the Select pointer.