Halstan came back to me saying they no longer offer the Print-on-Demand. Here's what they wrote:
This could still prove good once one has an established relationship with music shops who are willing to buy at least 10 copies of each title (unlikely?).It has proven to be uneconomical for us and the customers in the long run. Due to the high manual effort for a single product, we would have had to increase prices to a level that no one is willing to pay. We produce runs of 10 or more and then deliver them to 1 address
Does anyone of you know of any other service that does print-on-demand and delivery for 1+ copies?
I am inquiring myself around and will report back if I find anything.
I see editions like Musedita which are based in Italy but are distributed globally, so there must be something.
The other printer, Lightning Source UK, has not replied yet.