Fitting modern group on vinatge/old frames

is the OLD 130mm though?

It's 130 on the rear, otherwise was gonna get LBS to coldset it.
It's not necessary to cold-set: it's only 2mm either side and steel has plenty of "spring" for that; it does make life a little easier when getting the wheel in and out though.

There is one thing to be careful of though and that's having enough clearance between the top sprocket and the chainstay, particularly with 10 and 11 speed cassettes.