Wow! This surprises me as I would have expected there to be a specially stamped tunnel piece for 4-speed cars.
Were early to mid-1960s cars done the same? If not, then perhaps by 1969 the market for 4-gear cars was known to be small, so it was more cost-effective to just hack it out, since the customer would most likely never see it anyhow. Still surprised, either way.
I had a buddy who worked at GM Oshawa back in the 60'S. He has since passed away, he had collection of 66 Chev B bodies. He told me about them cutting the 4 spd hole. Just use "the gas axe" the line workers were told....I've seen 2-3 of these and for sure the cutter did not have a steady hand....LOL