I've seen two in two LGS shelves. A nickle 6" M29 that sat their unsold for nearly a year, and a blue M36 that is still there after 9 months.
Low production, matched with low demand here in CA anyway.
The problem is, I think, that the people who like classics don't want guns with internal locks -- so they buy used.
Also the price of the new Classics are high.
I considered the nickle M29 as it was beautiful, but it had a clocked barrel.