(First letter) "I'm a high-functioning Aspie top - and probably have sex work to thank for that. When reading people is your job you learn how to break it down and evaluate the signs eventually, or you don't eat! I've had clients, platonic friends, and lovers with Asperger's, also.
Possibly the best thing he could do is try to find a playmate that's also an Aspie - specifically a high-functioning one (likely to never have been diagnosed). They'll be able to read his cues somewhat while understanding his mindset, how he thinks, and the kinds of communications and instructions he'll have to receive. I do agree he shouldn't advertise in his dating profile that he has Asperger's, however it might help simply to state the facts on interacting with a new potential top: "I apologize in advance, but I don't always read subtle cues very well, especially socially. The more literal you can be the better - I want to do my best to understand and follow your wishes" goes a long way. If they're in the know, they'll be clued in, and even if they're not, they'll get it and know how to respond.
As far as actually finding this person goes, he can try geek haunts and Aspie haunts as well as kinky venues. The levels of overlap have become a cliché...
I think the advice you gave about when to disclose was great. As far as face-to-face venues, it's funny, but he might be best served to try to find an environment with some level of stated (rather than unspoken) etiquette or protocol. Casual situations are often the hardest because the rules of the game are so unclear. If at least some of the mores are stated upfront he'll feel more confident going in which will make all the difference.
In time, his weakness will also be his strength - he'll be able to use his pattern-finding, logical, literal mind to anticipate his Master's needs and wishes. He just might need more sample data to get there at first."***
(Second letter) "I have had the pleasure of having my questions answered by you, Monk, and Max the times and your question related to the BDSM/Autism overlaps my professional life a little bit, so I thought I might at least attempt to offer a coherent opinion. Professionally I work with teenagers with sexually acting out issues (read as poor limits, poor communication skills, social interpretations, etc) that have gotten them into legal issues. The large majority of the students I work with are somewhere on the autism spectrum and face challenges like your reader mentioned about social cues, non-verbal communication, etc--all things that are vitally important when discussing negotiation in BDSM, safety limits, and all the facets that go into the before-the-scenes work.
As this reader goes out in search of their experiences, I think your suggestion of a spotter/canary is ideal. Someone who isn't is knowledgeable about the local BDSM Community, but is able to help assist with communication and sometimes translate between the people in the scene could be helpful until the reader begins to pick up on cues academically rather than internalize them non-verbally as many non-spectrum/Asperger’s/autism people do. I think the reader's decision to communicate their individual circumstances is also important. I think many tops expect effective communication from the other half of the scene either verbally or non verbally. Knowing in advance that the person you have hog-tied with a tens unit attached to the good china may not respond the way you expect them to is probably vitally important.
I would also say that once the reader has made some positive connections in their community having partners that they get to know (like in any good relationship) the social anxiety will go down. There won’t be the fear that the top will go too far, or that the lack of effective communication will put someone in an unsafe situation."***(Third letter) "I thought I'd point out one potential resource the letter writer might want to look into: FetLife.com. If he joins and does a search on groups for neurodiverse kinksters there are a number of communities that may be of use to him. I think connecting with others with Asperger’s Syndrome and other non-neurotypical kinksters will help him find valuable help that is specific to his situation instead of just the general social anxiety assistance that's out there. Finding a mentor who has dealt with similar problems could go a long way towards helping him. Once he has learned from someone else's experiences and has a few new mental tools under his belt, he'll be better equipped to start looking for partners."***
My readers rock! Thank you for the information and support. This is how a community should work, so kudos to you for taking the time to be helpful!