Is anyone aware of a prototype sponsor that offers a prototype plan for an employee association to offer a Roth IRA under IRC section 408©?

Under section 408© of the IRC, and employee association can establish a traditional IRA and/or a Roth IRA for its members. I have an employee association as a client that has already established a traditional IRA through the opinion letter process, that now wants to establish a Roth IRA for its members.

According to the IRS, since the opinion letter process is not currently open for Roth IRAs, the employee association must obtain a document provided by a prototype sponsor to establish the Roth IRA. The problem is finding a prototype sponsor that has a prototype document for an employee association to establish a Roth IRA.

I would greatly appreciate any assistance in finding such a prototype sponsor.