I have a Richmond 5sp as well and also have developed a leak at the front - most likely the bearing retainer. The difference here is that I had a precautionary overall while my motor was being rebuilt so this leak is particularly annoying. Like you I'm afraid the tranny is going to have to come out - arghh!
Let me know what you find as I am just topping off my tranny ever couple of weeks so I can tackle the problem later this fall. Best wishes!