[slotloco]

One thing to be aware of with the Hudy. - The drive shaft to which you attach the wheels, is stated as being 3/32 inch which is equal to 2.38125 mm

- It isn't.
If it was, an NSR wheel with a 2.37mm hole would not fit on the axle, and the common 2.38mm wheels of different brands would be somewhere between press on and sodded tight.
The 2.38mm aren't tight, they have a bit of play.
The 2.37mm NSR also slide on easily with a little less play.
I estimate the diameter of the shaft end where you mount the wheel, to be around 2.36mm

I bought 2 more original axles for mine, assuming the original was worn - It wasn't.
All three were the same, and my multiple emails to Hudy went unanswered.
I had a thread about this issue on SCI forum a few years back. I received mixed answers, but the most credible were from a couple of car builders I knew and respected, who said that they had noted the same. 
One had put up with it as being "near enough and unavoidable", the other had replaced the original hudy axle with one he made himself, by turning down one end of some 3mm stainless steel stock. 
By coincidence, Hudy and NSR used identical diameter ball-races for the main drive shaft in their lathes,  which have the wheel mount as a smaller diameter at the end - that is about 2.97mm as best I could tell, because I had to polish down some 3mm myself with sandpaper in my lathe to get it to slide into either.

SO I made up 3 axles for my Hudy and my NSR, all to fit those 2.97mm ball-races, with 2.38mm "stubs" at the end. For one I turned down 3mm stainless, for the others I (possibly getting lucky on lathe runout error), drilled out some 3mm brass tube to 3/32nd hole diameter, then rammed a Slot.it axle up it with my lathe spinning. Finishing off by polishing that brass outer tube until it would fit into both the NSR and Hudy lathe drive post bearings.

So depending upon how fussy you are with your tyre trueing, you may need to do the something similar. 
-Unless of course, Hudy have changed something in the last 7 years or so, but I doubt it.

A short fix alternative, is to coat the original axle with superglue or nail varnish, and polish that new surface coating until the chosen wheels slide onto the axle but don't have any "wobble-play"