I can only attest to the engine's history since 1976. When I bought it.
Until two teeks ago it was covered in grease (on the block) like it has been since 1987 when I removed it from my car.
My guess is the blue and Chevy orange still visible are the only two times the engine's been painted in it's life.
As for what happened to it before I bought it I can't say? I just know it's listed as a '68 327 and I bought it out of a '68 BelAir for $75 complete in 1976.