I ended up buying some fakley Split jackets from Aliexpress. Took a month to come, but turned up eventually. Not bad, have 3 lenses, a big case and a Lance Armstrong cardboard box :)
I’ve put my Oakley prescription lenses from my real Split jackets in them and they fit, but one side is a bit loose. Works fine on the bike. The new frame actually fits better as I guess the old frame has stretched over the keys and now has a tendency to slip off when i look down.
Not bad for 15 quid or whateva. Will do me until I can order some new (real) Racing Jackets with prescription transitions :)