It depends on the scope. I can't say for sure but I don't think any 160's have been made for a while. Roland is the only one who makes the lenses and it seems from following the AP group he tends to make
certain models in a batch.
For example he is making 25 of the new Astrograph - Riccardi Honders F3.
He made about 60 AP140s when they first came out about 2 years ago and then the 130 Gran Tourismo seemed to make about 60 or so of those.
He has posted before that he makes about 200 scopes a year.