5101P is discontinued and thus no longer being produced. 5004 still in extremely slow production. Straight from senior PP personnel at Basel.
The interesting thing is that my guess is that the total production run of 5101P has been less than 100 and yet it does not seem a very appreciated reference by collectors, if the secondary market is correlated with collector appreciation. The 5004, on the other hand, is probably the most difficult PP to get allocated, even compared to the repeaters, as they make so few and is probably the most sought after in the grey market. In my opinion, 2 of the most wonderful PPs made.
Roberto