Hey @chas! Glad you’ve got some answers. Please note that we frown on simultaneous cross-posting here (see: FAQ: Is it OK if I cross-post?).
If you cross-post here because your question hasn’t found any answers elsewhere within a reasonable amount of time, we ask that you state up front that it’s a cross-post, include a link to the other post, and update here if you get an answer somewhere else. The idea is that it is polite to be transparent and try to avoid wasting helpers’ time.