At present we do not have an efficient mean or policy for the dissemination of restart files. They are not on the ESG and are only available via NCAR's mass store. If you already have an account, you can access the restart files directly.
Depending upon how labor intensive it is, we may be able to provide one or two restart files if you can tell us which case and which year you are interested in.
At some point in the future we may determine that we can not provide any restart files b/c of lack of manpower to dig them out of storage. All of that is still up in the air, so please bear with us.
Access to ESG is completely open, however, there are some history datasets that are available only to those people who register and request access to it, primarily the CCSM data. Since I'm one of the people who approves account requests, if you make it clear in your statement of work that you want access to CCSM data, I'll place you in the CCSM group. As Sylvia noted, if you have access to the NCAR MSS, you can get at CCSM data on it without using ESG, if you so choose.
Eventually all data serviced by ESG will be completely open to all who properly register.