Here in San Luis Obispo, California; I have observed M8a on 5900 KHz starting about 05:00 utc with a repeat transmission on 5800 KHz starting about 06:00 UTC. It's been awhile since I have monitored these transmissions. There is also a Spanish Language Catholic Broadcaster in the general nieghborhood that never clashes with M8a- almost looks like some frequency coordination. Mere coincidence; howerver, they are polite. More observations of this the better.
Although not a fresh tip; you might want to try: 5810 KHz starting about 06:00 UTC for more M8a CW. I believe credit goes to LanceLovejoy from St Louis for observing and listing this transmission. The first, and so far only time I have observed SK01 was on 5810 KHz. The parallel transmission for this 5810 KHz transmission, at present escapes me. Should be somewhere near, either an hour earlier or later. Often, you will hear more open carrior than anything else; at least, you know what frequency they do use. Again the ENIGMA Newsletter has a lot of good information about these Cuban Transmissions.
The Transmitter site for the Catholic Broadcaster I mentioned is I believe located in New Mexico. It is intended for Spanish Language Listeners in the U.S.A. As soon as they go off the air; often times M8a comes up on or near the same frequency. I just find it curious that's all- Liberation Theology at play here? That's all I'm going to say, I don't coordinate these Frequencies.
Thank You very much for resource list; very helpfull.