Does the RCC accept this as valid or invalid ? And, if invalid …how do Protestants receive their Sealing in the H.S. … apart from the Cath. Church ?
They don’t. Not to be blunt about it, but it’s the simple truth. Everyone receives the Holy Spirit (and of course, the Father and Son) at Baptism. For Protestants (or to put it a different way, all those communities arising from the Reformation), there simply is no Sacrament of being sealed with the Holy Spirit.
Where in the CCC, or Catholic writings of the Fathers, is this topic dealt with ?
Catechism
vatican.va/archive/ENG0015/__P3U.HTM
V. The Minister of Confirmation
1312 The original minister of Confirmation is the bishop.128 In the East, ordinarily the priest who baptizes also immediately confers Confirmation in one and the same celebration. But he does so with sacred chrism consecrated by the patriarch or the bishop, thus expressing the apostolic unity of the Church whose bonds are strengthened by the sacrament of Confirmation. In the Latin Church, the same discipline applies to the Baptism of adults or to the reception into full communion with the Church of a person baptized in another Christian community that does not have valid Confirmation.129
Footnote 129 refers to canon 882 The ordinary minister of confirmation is a bishop; a presbyter provided with this faculty in virtue of universal law or the special grant of the competent authority also confers this sacrament validly.
1313 In the Latin Rite, the ordinary minister of Confirmation is the bishop.130 Although the bishop may for grave reasons concede to priests the faculty of administering Confirmation,131 it is appropriate from the very meaning of the sacrament that he should confer it himself, mindful that the celebration of Confirmation has been temporally separated from Baptism for this reason. Bishops are the successors of the apostles. They have received the fullness of the sacrament of Holy Orders. the administration of this sacrament by them demonstrates clearly that its effect is to unite those who receive it more closely to the Church, to her apostolic origins, and to her mission of bearing witness to Christ.
1314 If a Christian is in danger of death, any priest should give him Confirmation.132 Indeed the Church desires that none of her children, even the youngest, should depart this world without having been perfected by the Holy Spirit with the gift of Christ’s fullness.
Although it’s not stated in the text itself, when the Catechism says “bishop” and “priest” it obviously means a
validly ordained bishop or priest.
Note: the numbers within the paragraphs are footnotes–which I did not bother to excise, as I normally do, since they make it difficult to read. Sorry.