Replacement Tuners for Guild T-50

The original tuners on my ‘62 Guild T-50 are extremely hard to turn, I’ve tried
lubricating and it hasn’t helped one bit! Is there replacements available that
won’t require any drilling or modifications to the guitar?

If you want to keep the same vibe and weight, Waverly makes a great open back tuner that you can get at Stuart MacDonald, personally I put grovers on pretty much everything.

My refin T-100DP came with Waverlies which work great, but they're pricey. Check out Gotohs too. They make quality repro tuners that are affordable.