Moin U-48,
it would be easier to use OH´s 'cameras.dat' and apply the widescreen mod changes to it than the other way round. I´m already in contact with 'Rubini' and planning to release a widescreen fix too. But if you can´t wait, go ahead and do it yourself. Here´s a bit of advise.
Browse to:
For each cam entry in cameras.dat you´ll have to adjust the aperture angle (AngularAngle) and -most important- the 'viewport right' value. I recommend to copy the data from 'Rubini's' ws mod cameras.dat and just paste them into OH´s version of the file. That should do the trick.
Have fun modding,
DD