Petimar,
You may want to visit the "Jobs" section of
+++ The Steel Guitar Forum +++. While many of the posts are for road work several prominent steel guitar players like Doug Jernigan are looking for session work offers. Many of the forum members are musicians that play, or played in, western swing bands.
Do you favor the style of any particular musician? Are there some specific songs that come to mind when you think western swing?
Another thought is to use a service like fiverr to search for musicians.
+++ HERE +++ is the results of a pedal steel guitar search.