This has NOTHING to do with the 1962 vs. 1955 or older Missale issue.
The 1962 Missale was released around 1962, and was the last version of the Missale Romanum before Vatican II. That is why +ABL chose it. Otherwise you'd have SSPX priests each choosing a different Missale according to his own personal opinion and personality. +ABL had to standardize, for the sake of unity within the SSPX.
To see what the early Traditional Movement was like, just look at the Resistance today.
The choice of pre-Vatican II Missale has nothing to do with any of the Indults "granted" by the Conciliar Church to say the Tridentine Mass (1983, 1988, 2006). You can be completely against the Indult, completely against the Conciliar Church, and still use the 1962 Missale.