.. sawdust & glue - you're not in ther antiques business by any chance?
With regards to the Lidl spray paints, I've no experience of the laquer (I was going to buy sone then I thought it might be too glossy for I wanted), but I have used their other spray paints both on a heated towel rail and the spare wheel bracket on the back of the car - both items weather well after a couple of years.
As I type this, I'm waiting for the first coat to dry (refurbing the microwave where the turntable ring has worn the oven bottom). Good stuff but just check its suitablility for particular plastics - you might need a primer.
Mick