Yes, I learned to fly without gyros, back in the middle to late 70's, never actually bought or installed a gyro till I bought a Concept 30 DX in 1990 and found the little 30-powered heli just too twitchy to fly without.
We were still making helicopter parts out of dinosaur bones then, and since oil and petroleum products hadn't actually formed by then, were forced to distill our own nitromethane and alcohol out of partially decomposed Pterodactyls that still roamed Montana at the time.
Stuff I flew without gyros? Schluter Heliboy, Helistar, MiniBoy, Champion, Superior, GMP Cobra and Cricket, American RC Helicopters Revolution (although technically, that piece of junk never left the ground under its own power), Kavan Jet Ranger, an xCell 60 heli that would be the equivalent of today's Miniature Aircraft Sport Trainer 60, and a Concept 60.
Of course, many of those helis were also flown with non-computerized, 4 and 5 -channel AM airplane radios and lots of bellcranks and linkages. The Schluter stuff became much easier when the early heli radios were introduced and FM radios became readily available (Airtronics, JR Century VII, Futaba 7F-GHI).
The learning curve was long and expensive, mainly due to the absence of the gyro. Learning to control the tail WHILE learning to hover was not a cake walk. Today's Heading Hold gyros make life much easier for the newbie as you really don't have to pay much attention to the tail when learning to fly these days.
About 1972 -- AM four channel radio, no gyro, barely any helicopter:
Miniboy, Futaba FP-5FN AM 5-channel radio, no gyro...and flew very well. First heli I successfully looped with, about 1982...