You might be able to straighten them using a padded vise. (put more than just the tip in the vise.) It might not hurt to heat the tip area with a blow drier so you are not cold setting. (A hair drier will be no worse than a glovebox on a hot summer day, so should not affect the heat treat.)
There is a chance of snapping the tip though, be the blade be warm or cold. Especially if the prior owner tried to straighten or did straighten it some.
Personally, depending on how bad they were, I probably would not worry about it. If I were a collector, I'd just use them for display, with the blade open. The bent tip might not be noticeable then.
I do not know if Buck's SPA service can or does straighten a bent tip. It would not hurt to ask them before trying to straighten them yourself.