Deep Sea Supply replaced the bladder on my travel wing, the price was right and turn around was a week.
I doupt if I had the right tools in the garage to do it myself anyhow but their lawyers probably don’t allow direct sales of bladders.
I once did a mod on my daughters BC making it easier to dump the weights and forwarded the idea to Oceanic, the reply was a threatning letter from their legal department. No such problems with BP&W, we can build, mix and modify any way we want :)