I'd sell it for $50 (i.e., let it be someone else's expensive headache) or donate it to a bike co-op.
The comment earlier in the thread saying that the steel Raleigh would outlast the Trek hybrid reminds me of something a car mechanic said to me decades ago: "People with Volvos say they buy them because they're so reliable. What they don't realize is that they're reliable only because they're willing to spend whatever it takes to keep them running."