MTB Chain Keeper for E-Type low direct mount remix

Inspired by [ranellucci](https://www.thingiverse.com/ranellucci)'s question on the [original thing](https://www.thingiverse.com/thing:3106125/comments) looking for a 38t version of the chain guide. [Ficacador](https://www.thingiverse.com/ficacador) - the original designer - said he didn't have the original CAD files so couldn't provide the 38t version. I looked at the design of the original, and it was a pretty clean, simple, elegant design, and I thought I might be able to help out. I'm having