Im kind of late to this conversation, but maybe this will help
someone... Or someone has any ideas.

I too have been using my Questus Radar mount, for almost 7 years now,
the last 5 activily cruising. It has been an excellent piece of
equipment. HOWEVER:

1. The original factory-supplied aluminum backstay pole has a major
case of aluminum pox. Annodized aluminum poles do NOT belong on a
boat at sea. Probably why they have a stainless option now...

2. Due to the necessity of adding a wind generator (and not wanting
the blades to impact the radar) I recently wanted to convert my
backstay mounted Questus to a mast mount. Per the manufacturer: $500
for a new casting with "hinges", plus $275 for a new cradle, plus $150
for a Raytheon adapter plate = $925!!! This is a bit over half the
price of a new unit.

3. The BIGGEST problem is that I cannot get the original aft-facing
cradle out of the Questus gimbal housing!! The stainless steel allen
head bolts actually protrude all the way thru the stainless steel
cradle arm, and are threaded into the aluminum housing. Even though
the unit was assembled using "Alumilastic" 7 years ago, the aluminum
housing-stainless bolt interface has become a solid unit. A torch and
several days of liquid wrench application later, I was able to get one
of the screws out, which left a smooth hole where the threads used to
be in the housing. The aluminum threads are now part of the stainless
steel bolt. The OTHER bolt however, has proven immobile. I have now
stripped out the allen head. And because the allen bolt penetrates
the stainless steel cradle completely (thru the aluminum gimbal),
there is no way to drill it out without buggering the aluminum
casting...

I guess there is a lesson here - add "dismantle and re-passivate every
stainless steel bolt into aluminum material fastener on your entire
boat once per year"...

Bummer that Performance Marine went bust. They were on the right
track with an all stainless design. Maybe I'll just trade my Tayana
37 for a Catamaran or a Tri, and not have to deal with all this
heeling stuff...