Yep, keeping this stuff going is kind of essential. Over the years, I have added RAM and replaced the hard drive in the MBP with a Solid State Drive. The other day, I visited the Genius Bar and had them run a diagnostic. All good except for the battery.
The original is tired and needs replacing. Apple said they don't repair old computers, so I went to OWC, (my favorite parts store) and ordered a new battery.
A new computer that runs the latest software would be nice but now that I'm retired, that kind of thing goes on the back burner until I can make some extra cash. I haven't run any graphics software for a few years now.
Maybe some day…