Anglican attempts, certainly invalid. The new rite, although not ideal, and not coming from Mother Church in Her perfect freedom, certainly valid.
I wrote an article critiquing Fr. Cekada's claim of doubtfulness (just like some people say God's existence or the Resurrection is "doubtful" because they doubt it; not at all - it is objectively certain by clear criteria. One's subjective doubts on those must be cleared up by prayer and study), in brief: is it doubtful that the Apostles were Bishops? No. No. No
It borders on the patently ridiculous to say the ancient rite in the Apostolic Tradition of St. Hippolytus is invalid. If so, the Coptic and West Syrian rites are invalid as well. And even with Fr. Cekada's exaggerated criteria, the validity remains. Just see the number of allusions to the specific power of the episcopacy/high priesthood/shepherds of the flock/bishops. Fr. Cekada's objection clearly fails here.
"Let the bishop be ordained after he has been chosen by all the people. When he has been named and shall please all, let him, with the presbytery and such bishops as may be present, assemble with the people on a Sunday. While all give their consent, the bishops shall lay their hands upon him, and the presbytery shall stand by in silence. All indeed shall keep silent, praying in their heart for the descent of the Spirit. Then one of the bishops who are present shall, at the request of all, lay his hand on him who is [to be] ordained bishop, and shall pray as follows, saying:
‘God and Father of our Lord Jesus Christ, Father of mercies and God of all comfort, who dwellest on high yet hast respect to the lowly, who knowest all things before they come to pass. Thou hast appointed the borders of thy church by the word of thy grace, predestinating from the beginning the righteous race of Abraham. And making them princes and priests, and leaving not thy sanctuary without a ministry, thou hast from the beginning of the world been well pleased to be glorified among those whom thou hast chosen. Pour forth now that power, which is thine, of Thy Principal Spirit, which thou gavest to thy beloved Servant Jesus Christ, which he bestowed on his holy apostles, who established the church in every place, the church which thou hast sanctified unto unceasing glory and praise of thy name. Thou who knowest the hearts of all, grant to this thy servant, whom thou hast chosen to be bishop, [to feed thy holy flock] and to serve as thy high priest without blame, ministering night and day, to propitiate thy countenance without ceasing and to offer thee the gifts of thy holy church. And by the Spirit of high-priesthood to have authority to remit sins according to thy commandment, to assign the lots according to thy precept, to loose every bond according to the authority which thou gavest to thy apostles, and to please thee in meekness and purity of heart, offering to thee an odour of sweet savour. Through thy Servant Jesus Christ our Lord, through whom be to thee glory, might, honour, with [the] Holy Spirit in [the] holy church, both now and always and world without end. Amen'." (The Apostolic Tradition of St. Hyppolitus).
Fr. Cekada's claim is that the specific power of episcopal authority is not mentioned here. Unfortunately, that seems plainly erroneous.
1. The rite asks for the Spirit given by Christ to His holy Apostles. Will any one whomsoever venture to doubt that the Apostles were Bishops? Incredible! If not, the specific order is mentioned.
2. Mention is also made of high priesthood [summus sacerdos] which is just another term sacred Tradition, the Fathers and ancient liturgies use for the episcopacy. By analogy with the three grades of order that existed in ancient Israel, the deacons are levites, simple priests are priests and bishops are high priests. This analogy is pointed out often by the Church Fathers. It is clear in the rite above that the specific grace of the Spirit of the High Priesthood or the Episcopal Authority given to the Apostles is being conferred. It is not doubtful that high priesthood is univocal. Simple priests are not high priests. Therefore, the rite is valid.
3. Finally, Our Lord Jesus is Himself the Great High Priest and Chief Shepherd of the flock. The Father annointed and consecrated Him as such. The Lord said He gives to the Apostles the authority His Father gave Him. In the rite above, though the specific mention of the Spirit given to the Apostles should by itself settle the matter that this is a clear reference to episcopal power, the portion "thy royal Spirit, which thou gavest to thy beloved Servant Jesus Christ, which he bestowed on his holy apostles" only renders it even more certain, as Jesus certainly was the great High Priest, just as His Apostles were certainly Bishops. Both are not doubtful at all.
So, the allegation that there is no specific mention of the episcopacy here seems wrong. Fr. Cekada's thesis stands or falls on that point.