Transformer question (only slightly OT)

I have a power transformer that I scavenged out of a 15-year old UPS, so it's probably pretty close to being on-topic. At any rate, I want to use this transformer in a DC power supply. I have three sets of windings: two sets are 120/240v "universal" series/parallel type and the third is 24-0-24v center-tapped. I want to run this from 120vac. Is there any benefit to paralleling the two sets of 120/240v main windings (i.e. 4 120v windings in parallel)? Will it increase the power rating of the unit or is that mostly a function of the secondary winding? Suppose instead of 24-0-24 on the secondary, I'd like 12-0-12. Obviously, one way to get this is to hook the primary (-ies) up as 240v. Is there any benefit to be gained in parallelling the two 240v primaries? Thanks, Chuck