2Nothing in the foregoing paragraph shall be construed—
(a)as affecting the rate of any employer's insurance contribution ; or
(b)as excepting any person who pays, or is liable to pay, an employer's insurance contribution, or as conferring any power to except any such person, from liability to pay the tax ; or
(c)as conferring any power to modify the rate of the tax in relation to any class of persons ; or
(d)as prejudicing the operation of section 2 of the [1965 c. 54.] National Health Service Contributions Act 1965, section 28 of the [1965 c. 62.] Redundancy Payments Act 1965, section 38 of the [1965 c. 19 (N.I.).] Contracts of Employment and Redundancy Payments Act (Northern Ireland) 1965 or section 2 of the [1966 c. 7 (N.I.).] Health Service Contributions Act (Northern Ireland) 1966 (which make corresponding provision with respect to payments under those Acts).