That SR71 did not use a cluster and was the Centuri Magnum-D SR71.
It is even listed as a Centuri kit in that Estes catalog.
The only time Centuri kits appeared in Estes catalogs was in the "seasonal special" catalogs.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !