Blimey chaps this is getting complicated! I have already covered part of the deck in veneer so dont fancy stripping off to start again (lession learnt for next time) and was going to follow the Veron plan as is. I must say some of your work is fantastic, well worth the effort.
I tried some pencil lines on a scrap of veneer last night but they got a bit lost when stain applied. I then tried marking the lines then scoring the pencil lines with a sharp blade a few times, then opened up the cut with a thicker penknife blade. This, when stained, showed up a lot better as the cuts took on the stain. I suppose I have almost ended up with seperate planks, its just they have been cut from the sheet after sticking down!
I'm going to stain again tonight then give them a coat of epoxy resin and see how it turns out.