Took the frame out of the stand and weighed it this morning. 6.4lb before filing (not that that will take much weight off). Not 'lightweight', but much lighter than the donor frame at ~10lbs.
Also put it back in the jig to check the alignment and it fit almost perfectly. The HT post had to be moved back ~2mm to fit. But, the HT angle is still good (measured at 70.8deg from 71 as laid out). BB post and rear dropouts were perfect. The dropouts closed up maybe 1mm.