For what it's worth, the 2004 calendar put out by the Angelus Press (SSPX) lists May 1 as the feast day of St. Joseph the Workman.
Of course they do...the SSPX does follow the 1962 Calendar. What I witnessed, however, was 2 individual priests of the SSPX refuse to say the Mass of St. Joseph the Worker.
More common, however, is the fact that everywhere I have been in the SSPX, they downplay the feast. They say the Mass, yes, but there is a never a High Mass for it, Vespers, or even a mention of it from the pulpit. On the other hand, the Feast of St. Joseph on March 19th. is always observed with great solemnity. So, what I don't understand is why they do not afford the same honors to St. Joseph on his other feast with all the extra pomp that is becoming of a first class feast.
The fact that the feast this year fell on Sunday sort of forced them to celebrate it with more solemnity this year.