I bought some wheels from one of the companies selling pit bikes and also sets of front and rear wheels.  They'd broken up a few sets to send out rear wheels to people who had bought pit bikes and broken their rear wheels and so had a few front wheels left over.  I think it was pitbikeparts.co.uk, but can't remember at the moment - but presumably you could call any of the suppliers selling sets of wheels - I phoned a few before I had any luck and I suspect it'll just depend on their stock at the time.  I got my original set of wheels from funbikes but they had knobbly tyres and inner tubes and cost a lot more.  I did try getting just the front wheels from a manufacturer in via Alibaba but failed.  Good luck.

We buy our Pit Bike wheels + - 28 € in this shop
Maybe look at the cost of transportation ....

https://www.wkx-racing.com/121-jante-pit-bike-dirt-bike

Thanks .  Had a look at your recommended site .  Would that be the "Steel Front 17" axis 15 mm you use ?  Part number 0410300200114

Rhys is absolutely right about bearing size. However the last time I looked 17" pit bike wheels were becoming scarce in the uk and had risen in price, due I presume to the number of enquiries. I understand that shipping costs have also risen sharply now, due to covid19! Gemini Karts are struggling to get hold of any from overseas and if successful will be months away, with no guarantee of competitive cost.
If the wheels from France are 35 OD, it seems a good option.
Has anybody found a source in the UK recently?

It seems impossible to find decent wheels for a sensible price whether new or second hand, all I can see on facebook marketplace is random mismatched ones missing spokes !!

 I spotted he has a pair of 14 inch wheels, I'm a massive tighwad atm as redundancy is looming so have been looking under the bottom of the barrel which incidenty is providing lots of £10 per wheel listings where they are all mismatched!

I'll keep that in mind, I've got to sell a few bits which will free up funds!

Just to throw something else into this pot of stew!
While pitbike wheels have been found to be a very good option, it's still not "the only game in town". Graham Hill purchased wheels for his MG, they are neither the original Honda CT type wheels, nor are they Pitbike, "Bentaxle" on the US forum site uses yet another well known brand of wheels from small moto x bikes.
I guess what I'm suggesting is that there are always options to explore. Some may be a bit more expensive, some are cheaper. It's usually worth spending more time trolling for options.