That's a really nice find. quite a document and a nice look back at how things were done. Unions in general have changed a lot, and quite often, not for the better.
Suffice it to say, in spite of union leadership, most of the rank & file trade union guys don't view public sector "unions" as "brothers", or vote lockstep for a particular party, simply not so anymore.
Current union leadership in a lot of cases are struggling to stay relevant while riding a declining entity that they can collect the "taxes" from.
One striking example, when I joined the Plasterers & Cement Masons union in 1980, part of the swearing ceremony after serving a 3 yr apprenticeship was an oath to not join or support any Communist party group. That section is GONE from the charter, and ceremony now.
6 or 8 yrs ago Richard Trumka, head of the AFLCIO, marched in the same labor day parade in DC as a contingent of a communist labor group, something utterly unimaginable when the contract posted above was written.