You will probably need the B-Nova adapters so that the slot.it guides will fit without too much slop. The adapters can be found online, and can also be used to repair broken guide mounts.
As for the slot.it guides, usually the universal screw mount one is the best for this situation.
Note that you'll also need slot.it (or similar) braid, as well as eyelets for the wires, so that you can hook up the wires to the braids just like in a stock slot.it car. JP Slot sells a kit that comes with new wire, eyelets, and their nice copper braid all in one pack, but you can also get all that stuff from slot.it.

 

Thanks Mr Flippant that answers my question perfectly.

Andy P

 

Do the B-Nova adapters work with other guides? I like the Ninco sprung guides, for example, so I wonder about them in Scalextric cars. I've just ordered some of the adapters, so I suppose I'll be able to answer this question myself before too long. . .
(I do plan to rid myself of the quick change discs on my Scalextric cars and replace them with decent honest hard working eyelets and pieces of braid, one by one.)

 

OP why are guides breaking? Too much magnet and the tail snaps around?

Anyhow I have tried the B - Nova adaptors when I have broken a guide holder. They are so-so. I find they tend to break as well

If your Scaley guide is not broken just replace the braid with copper. THis is how I do it. I was shown this by Chris Walker.

Excuse poor pics.

Cut and bend two pieces of copper braid in a n L shape.

Sand the top of the disc to roughen then Super Glue braid to disc like this

Trim braid so they are even then squeeze with pliers to flatten them even more. Insert disc in usual manner and away we go.

 

Just get a slot it screw in guide and it fits fine

 

I have just converted a Hornby MC12 guide. Looking at this B-Nova thingy. and trying to find stockiest with the UK. I found an old Hornby chassis. So cut out the complete guide bracket, sanded it down. to fit the MC12. And........ I think I'll be doing this to all my Hornby quick release guides.
I wish someone at Hornby would redesign their motor mounts. Taking a motor out is very hit and miss. The lugs that hold the motor in...SNAP.