I've been without a bike for ~3yrs now (previously cb350) and only recently picked up a '75 GT250, ~2500 miles.
Low-bars, grips, seat, side-stand, and signals are the only non-stock items I have picked up on.
I plan to replace the grips, side-stand, signals, front pads, and tires in short order.
The issues I have seen with the bike include a finicky "F" light between the gauges, flashers not flashing, and suspected crank seal leakage.
I truly enjoy the bike thus-far, but look forward to learning the in's-and-out's of it (which brings me here).

--billyM