I've been advised not to power it up

Good advice. Let the new owner risk frying the power transformer if he wants
to fire it up before replacing the capacitors (see
http://antiqueradio.org/halli12.htm ).

At a glance, looks like it's in reasonable condition. Nitpick: missing a
piece from the clutch (brake?) assembly for the main tuner in front, but
aren't they all? I have two SX-28's. One is missing those parts, the other
one has them.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html