gevent 1.0.x (and almost all other versions ever created) remains on PyPI where it can be installed with pip. Here's one way to list available versions:
$ pip install gevent==dne
Collecting gevent==dne
Could not find a version that satisfies the requirement gevent==dne (from versions: 0.9.2, 0.9.3, 0.10.0, 0.11.0, 0.11.1, 0.11.2, 0.12.0, 0.12.1, 0.12.2, 0.13.0, 0.13.1, 0.13.2, 0.13.3, 0.13.4, 0.13.5, 0.13.6, 0.13.7, 0.13.8, 1.0, 1.0.1, 1.0.2, 1.1a1, 1.1a2, 1.1b1, 1.1b2, 1.1b3, 1.1b4, 1.1b5, 1.1b6, 1.1rc1, 1.1rc2, 1.1rc3, 1.1rc4, 1.1rc5, 1.1.0, 1.1.1)
Many of these are also tagged and/or have tarballs and binaries uploaded to github (
https://github.com/gevent/gevent/releases).