Terminated employees, business, and 401k plan. SEP IRA?

[spiritrider]

A small business with a 401k becomes unprofitable. It terminates all employees, the business and the 401k.

However, the business will receive payments for billed services for several months. This leads to a few questions:

1. Does the successor plan rule apply even though the business stopped operations and the employees received all contributions due them?
2. If the above answer is yes, can the owner adopt a 5305-SEP IRA (which is an exception) in the same plan year or must they adopt a prototype SEP IRA plan?
3. Or is there no way to make employer retirement plan contributions on this residual income?

[CuseFan]

A recent post in this forum discussed this issue in a similar context and the issue was raised that a new plan would be considered similarly to an amendment of the prior plan when looking at discrimination. That is, you terminate one plan with employees and start a new one in the same year but without employees and then provide an employer contribution in the second plan. Not saying yes or no, but it's a gray facts and circumstances situation.