The winner does happen to be my brother Ian, but there was no shenanigans, in fact I would have rather the winner be local as now I have to ship the prize overseas.
Ian’s second guess was
I would say it’s for marking the area to cut out in order to recess the rails in a balustrade, to ensure they are vertical, hence the spirit level
Which is bang on, the device is in fact the LJ-3047 – Telescoping Baluster Marking Tool, made by LJ Smith. To see it in operation I suggest you watch this YouTube video by Matt Weber.
I haven’t used it yet, but I’m sure I will. I think I paid the embarrassingly low price of eBay of $0.99, plus shipping.
Chris, I’ll also send you a pot as you were the only other entrant, Ian can deliver.
Ha ha, don’t worry. I knew it was some sort of marking gauge but couldn’t work out the level. $0.99, could you afford it 😉
Well if you ever want to borrow it let me know. Yes 99 cents was stretching it a bit!