(1) For the purpose of determining the statutory basis of existing units of local government, each unit of local government organized under the general statutes authorizing the municipal council-mayor form of government, which does not adopt a new form, shall be governed after May 2, 1977, by the following sections:
(a) 7-3-201;
(b) 7-3-202 (1);
(c) 7-3-203;
(d) 7-3-212 (2);
(e) 7-3-213 (3);
(f) 7-3-214 (2);
(g) 7-3-215 (2);
(h) 7-3-216 (2);
(i) 7-3-217 (1);
(j) 7-3-218 (2);
(k) 7-3-219 (1);
(l) 7-3-220 (1);
(m) 7-3-221 (3);
(n) 7-3-222 (2);
(o) 7-3-223 (2).
(2) This form has terms of 4 years for all elected officials. The size of the commission shall be established by ordinance, but it may not exceed 20 members.