I thought that Archbishop Lefebvre recognized the validity of the Novus Ordo ordinations.
You're right, Archbishop Lefebvre did recognize the validity of the new rite of Ordination. He also did not require conditional ordination for priests wishing to work with the SSPX. He even used the new rite himself (!) when he ordained Fr Cottard in 1973. Fr Cottard is still in the SSPX and attended last year's General Chapter. Then there was a Fr Stark in the early days who was a Jesuit ordained in the new rite and worked with the SSPX. Same as Fr Glover who was a canon lawyer. All this talk of the SSPX *always* requiring conditional ordination in years gone by (especially when Archbishop Lefebvre was still alive) is simply (and unfortunately) a myth.
However, whether he held the new rite of episcopal consecration to be valid is less clear.