As mentioned, get someone look at it from maintenance view and even better if that "someone" is familiar with TB:s. They are littlebit different than regular C:s and P:s. Nice aircraft but needs slight "french" thinking to work with.
Like all ageing GA aircrafts, these suffers corrosion as well. Maybe not issue, but worth to check to avoid nasty and costly surprices.
Think you know, but, engine with 400hrs left may start burn some money well before hours are gone. If there is history for some repairs, it may be good runner to the final end but if nothing major is done you may budget some cylinder repairs at least.