might even be somthing simple, for a change :grin- check to see if the little detente spring is broken / missing. its supposed to hold it in the gear. if its not that, the 1st gear synchro is most likley worn out...probably easiest to replace the tranny with another cheap used one, if thats the case. ( mondo work, but shouldnt be too expensive..it'll give you an excuse to do the clutch if it eeds it, too.)
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