Yes you're right I was referring to the 458-460 arrangement, I assumed it was a BA464 that had been swept into this as well. If it's a native IB flight, then obviously it will be full IB service (and paid for drinks in economy) on IB metal with IB crew. The clue is in the BA flight number, if it's a 400 series it's essentially a BA service or IB look-a-like, whereas 500+ is a core IB service.