@Vern Edwards Yes, all assumptions your made in response to my question are accurate.
FAR 16.601 (b)(1) states, "Direct labor hours at specified fixed hourly rates that include wages, overhead, general and administrative expenses, and profit".
So, based on that my read is T&M rate is a fixed type labor rate and should not be subject to probable cost adjustment for the purpose of evaluation!
However, I'm not sure I'm clear about the last comment you made regarding realism of ceiling price? If you can elaborate, please, that would be helpful. Thank you.