(2) An employees' trust which is described in
section 401(a) which is exempt from tax under
section 501(a), or an annuity plan described in
section 403(a), for the benefit of the registered owner, on or before the 60th day after the day on which he received the proceeds of such redemption. This subparagraph shall not apply in the case of a transfer to a trust or plan described in (c)(2) of this section unless no part of the purchase price of the retirement bond redeemed is attributable to any source other than a rollover contribution from such an employees' trust or annuity plan (other than an annuity plan or employees' trust forming part of a plan under which the individual was an employee within the meaning of
section 401(c)(1) at the time contributions were made on his behalf under the plan).