@kuduframes - you beauty!!! I owe you one. Big thank you. Not dealt with Lion yet. The artist did say "ideally" so if it ends up slightly narrower it shouldn't be a problem. She did give me a minimum and this moulding is within the range, just. It's deeper than planned, but I can pack it and I think she'll be fine. I said I'd do one, let her see it.
@not your average framer (Mark). Given I costed for a moulding of similar size to the one I drew, plus a fillet, the work cutting and putting it together, plus painting and this moulding comes in at less than that without the need for painting - my risk taking has paid off this time. Phew. It'll wash its face. She did let slip she rarely has so many to frame at once so I told her it was not a price I could do for a lesser quantity and I'd have to charge her more per frame, which she was all knods at. I'm hoping she'll come along with a lesser quantity several times over

We'll see! And I beleive you're right - I'm seeing these frames a lot just now. They seem to be trending among artists.
@jamesnkr & @steve N "how could I quote?" - see above. I spent a while talking this lady through this order, making sure I understood what I was getting into (because as you say... big jobs fill a workshop, etc.,). While I'm not going to make a lot on it, it will inject something into the old cash flow and should secure a potentially regular customer who'll pay more in future (see above again) and perhaps her artist friends will follow (I swore her to secrecy). May not work, but worth a try.
Thank you everyone. I'm off to crack-on now.