Lanstrom

I bought my Angelica model 9220 DN at Sam Ash in 1978. It's an exquisite replica of a M D-28 dreadnought. It's retained its rich tone and resonance and plays as well today as when new. Weak link are the machine heads. Getting a little drusy with age. These are the sealed Bakelite frame units - out of production for decades. Any guidance anyone could provide on optimum replacements would be appreciated.