Mac,
No it will not work.
The process involved to re-regulate these rifles is different to soft soldered doubles.
What ever you do, don't go applying tons of heat to try and melt the braze or you will very likely stuff the barrels completely.
There is a process that works well for re-regulating these rifles and when done properly is almost undetectable.
The job is quite involved and will test the regulators ability to the max!
Some doubles are quite easy to bring the barrel groups together during re-regulation but the Winchester Grand European is not one of them!
At some time I may do a story on how it is done if anyone is interested.
They are a damn good rifle for hunting all sorts of small and medium to large game, but there are a few things which need attention if the rifle is to be used a lot.