I gotta tell you, that Rustoleum paint is TOUGH! Being pig ignorant about such things, the mastic I used to build up the edges of the roads turned out to be the stuff that doesn't harden so I had to fetch it off. I wasn't worried about any possible damage to the foam base as that's easily repaired, but I didn't fancy the idea of having to mask everything to re-do the road surface.
Turns out I needn't have worried. I pulled most of it off with my fingers and fetched off the remaining bits using the edge of a wire brush. The road surface turned a slightly lighter grey, but that was the total extent of the damage. I can cause paint to fall off my models just by giving it a hard stare, so for this stuff to withstand some hard scrubbing with a brush was quite miraculous.
Anyway, I replaced the mastic with some Hard as Nails and splodged on a bit of paint. I'm not too worried it hasn't covered properly as I'll be putting lots of green stuff down.
I've also got some of the hedges fixed. For those that want to know, I'm using rubberised upholstery sheets. Unfortunately I can't find who I got them from at the moment, but I got a pack of three sheets about 9"x6"x1" thick for about £10. It's great stuff. It's already a mixture of green and brown fibres so no painting is needed. It can be cut and shaped with scissors (I've done this over a box to collect the offcuts for which I have plans) and glued with PVA. It's a little overscale for 15mm but I reckon it would be perfect for 1/35. It can be painted and extra flock can be sprinkled on if necessary using a spray glue. I've used about 11/2 sheets for what I've got on the board - mainly because I wanted fairly long lengths and a corner piece.
I also painted up the rough stone wall. I primed it with Stynylrez grey as it originally came in different coloured resin bits. I painted a random selection of bricks with browns and greys, then added an Ultimate light dirt wash and finished with a brightish green for the moulded 'grass'. I cleaned most of the wash off with a damp cotton bud and I think it looks OK.