The problem you might run into is about the safety 'beads' on rims - the 'ridge' or lip that keeps the tyre sidewall out against the rim. The reasoning behind that (I think it came in some time around the 1970s but don't know for sure) was that without that bead, if the tyre loses pressure, it could flop about and you'd lose all grip, possibly spin the car or roll it. With the bead on the rims, it still holds the tyre on (or at least better than with no bead at all) so you have more hope of controlling the car as you pull over and stop safely..
To that end, 'stretched' tyres end up putting the inside bead of the tyre at a bit more of an angle than if they were fitted to the 'right' sized rims, So it could compromise the tyre's ability to stay somewhat attached to the rim, in an emergency/blowout etc.
Which is part of the reason manufacturers nominate suitable (safe?) rim sizes.
I'm not saying this to preach, but rather to highlight why it could (even without specific legislation about stretched tyre combos as such) easily be grounds for the police to defect it. It'd be hard to argue the toss on it i would imagine.
On tyres in general - no experience with that brand. When I first got my coupe, to get it into my name, needed a roadworthy certificate. For the 'time being' I decided to just get some el cheapo tyres - hero brand, for hte roadworthy, and go to better tyres (and brakes, inside 13 inch mags). Anyway I thought I'd have them on there for a few weeks. What took me by surprise was how well the darn things (in 155/80 r12 size) gripped. They won't be scaring guys on mega buck street tyres, or circuit racers or anything like that, but it really surprised me. It gripped good enough that I decided to leave them on there until they were worn out (and I'm just getting to that stage, over 20,000km later). Now in the wet, they are decidedly less impressive. They don't grip well at all. Fine for a-b everyday wet weather driving, but you wouldn't want to be trying to driving sportily (is that even a word) in the wet. To be fair they are very predictable and consistent in the wet, just not that _good_ outright.
It was a few years ago, but I got them for (iirc) $55 each. That was their hr558 model. In the sizes you are discussing, they have them in a hr668, which is likely a very similar compound (tread looks similar too, just different/larger rim sizes catered to, and lower profile)
http://www.chapelcornertyres.com.au/files/DataHR668.pdfhttp://www.chapelcornertyres.com.au/hero.htmlI didn't actually buy them from there, but that site lists them, and their sizes. I would imagine their pricing was similar (naturally add some $$ to account for larger sizes, and a few years worth of inflation etc)
Last little tid-bit - definitely check out the tyres in person, or find pics of that specific model and size/profile on the same width rims as you have. The reason I say this is that, at least in my experience, with a few of the cheaper tyres, well their 205s (for hypothetical example) have a big radius at the edges of the tread, so they look more like the tread width of other brands of tyres in a 185 size. That'll certainly affect how 'severe' the stretched look will be for that combination
Good luck - and whichever set you end up going for - could you post back here with the brand, and how it looked/performed, or any other comments/feedback (and a pic or two as well!) ...