Cheers Steve, I was looking at the wrong end!
I'd expected the plastic pipe to be moulded into the intercooler body. Next time the bumper's off, I'll take a look as I've got a set of viton O rings in the toolbox. Not doing that again in a hurry.
I've run a bottle of Techron through last summer before the MOT and that worked well and I regularly dose up with Redex to keep it clean. Found an unopened bottle of Wynn's turbo cleaner I must have bought for the Mondeo, so that'll get chucked in the tank at the next refill.
The 160 upgrade is on the bigger plan, though the way she currently runs I'd say someone's already had a play around on that front.