I have some of these. I've had 'em for a couple years now. I never get around to using them. I don't know how potent they are or if they have degraded. I'm kinda in the same boat as you. I would probably use 50 for my first time. I think it should be a pretty moderate dose, I would definitely double-check though. Best to search some reports.
I got some HBWR, and I think I'd rather try that sooner than the corymbosa. I've been eating a lot of 2cs and such these past couple years. I kinda want to get back into the natural stuff. Use mushrooms more frequently... cactus juice... and some of the lsa seeds. Maybe I'll check the corymbosa out soon.