Hello LARRY
Talking off the top of my head on the MICARTA RISERS, to the best of my recollection Bear came out witht the Super Magnum in 1966 with a phenolic riser (bowling ball material). They kept this in the Super Magnum through 69. I think in 67 they also came out with the Tamerlane HC-30 and the Super Kodiak. In 68 & 69 The Super Kodiak was a phenolic riser with rosewood caps, and the HC-300 had the Phenolic/Rosewood riser. I assume that the phenolic riser is the same as the MICARTA that you are referring to.
After these years they went to FUTUREWOOD which was actually hardrock maple, dyed various colors, and impregnated with rosen. I understand that they would put the material in a vacuum and suck out any sap, then put it under pressure and forced rosen into the pours.
I am just about 99.99% sure tha I am right on the above info, but I coulkd be off a bit.