I don't really have much to add to the thread, but, having used our
88-note pushup player for concerts several times:

A tradesman-van with hatchback, a pair of (removable) motor-cycle
ramps, the help of 2 to 4 people, a custom-made (wood-) cover for the
keys, a custom-made (blanket-kind-of-type) cover over all, some straps
and bands as well as careful driving will always do the trick.  Even
then, be not too upset if you do get a scratch here or there.

The amazing thing about a pushup is always, what kind of instrument you
are getting provided.

Although tricky at times to match the right height it usually always
fits, but you can get the whole range of instruments that is out there:
old out-of-tune uprights to rather expensive Deco-style uprights, over
to small, medium and really large (and again expensive) excellent
playing and (re-)sounding "wings" (grand pianos).

The next thing is of course, what kind of room they are standing in,
as -- much too often -- they are either too loud or too quiet for the
purpose.  (Thus, in a setting of a concert with street organs, this
doesn't matter...)

For the case that there is either no instrument provided or no good
one (as it is either out of tune, missing strings or in complete
wrong height or length), we are always happy to have a rather
light-to-transport electronic piano that always works (and you can
even switch to harpsichord or organ!).

Just my 2 cents...

greetings by(e) InK - Ingmar Krause