@BLUEFROG — this works very nicely for what I need — thank you!
Also: As a long-time GoodReader user who has only just started exploring inking in PDFs in DTTG on iPad — I am very impressed so far with how well DTTG does inking (and PDF handling, more generally). I’m thinking I may well be able to take GoodReader out of the loop altogether. Kudos to the DT/DTTG team!