Steve,
I've seen several 4's with the 140 vne.
I believe the vne on the model 4 was predicated on the thickness of the windshield material used not the length of the wings. John McBean might be able to shine more light on this. The thinner windshields would start to deflect (push in ) at a lower speed . Mine will start to deflect very slightly at 140mph. . When I was building the model 4 in Murle Williams shop Mike Gibbs was building an almost identical version and his was also 140 vne. Both of our 4's had all the speedster mods except mine had the longer wings. Mike's by the way would hit 140mph straight and level at full throttle. His had wheel pants and the medium Ivo prop with a large spinner on it.