Hi all a mate got a set of 13 x 7" Road Rebels.  Sitting them on the axles the rim sticks out 15mm past the lip.  I always thought they fitted inside.  The rims are definitely supplied as 4 x 108 from new.  Anyone else had any trouble with them?

Depends on how you was checking them, if the car was with dangling axle on one side it will poke out more, ya know angle n stuff.
If they was tested (tyres off) , the best way is bolt the rim on to the hub and sit the rim on 4in wood blocks and lower the car to resting height will give a more accurate assessment.
Rebel rims of 7in should be the same as say minilite, globes, crosswires etc.

All depends on the offsets but I think you might struggle at the front.  I have 13x6 hotwires on mine that sit just outside the front guard.

Most of the Rebels I have seen tend to be fairly deep dished by default.
I think the rears would be fine, but 13x7 on front of a mk1 capri would most likely rub.
My 14x6 with 205/50  on minilights is about on the limit 

they stick out past the guards - but who cares - they're rebels