Indicator for private (or other) aircraft, own-battery op for at least an hour / own gyros etc. -- this ad on a TV program done by EAA on Pilots.
It can replace the normal indicator in panel, costs ~$3500 IIRC. This instrument repair facility was Thinking.
As the Nova program makes clear, there was a remedy available to crew, in absence of any pitot-derived info: keep +5-degrees and thrust at 85 (87?)%
== assures a flyable speed. At 35K' alt. -- there is only a small delta-V allowable (+/- 10 Knots!) without precipitating a stall,
then roll-over (for folks never trained for recovery from 'fighter-plane' type aerobatics.)
Windoze-controlled or no, I (still) look to Physics to provide an Other device for V/Alt determination, at least to precision needed at these altitudes,
given the rough enviro in which pitot tubes must operate and Not freeze up via super-cooled liquid mist (or any other nemesis.)
Luck.. you Passengers!