the actual transistor used for switch is ancient 2SD1252A (Panasonic)the custom zeners are random Red-LED + Д9К (apx. 2V + 320mV drop) other BJT-s are 2N3906(-04) but you can use a better ones such as fixed beta 2SA1015 , 2SC1815 ...
!note :: altough theLE50 is labelled as "Very Low Drop" it actually performs worse than 1 of those 78L05-s and the all three b_a_r_e_l_y manage the 150Ω load with reasonable output (4.8 dn2 4.7V) . . .
. . . when the brought regulator does 100Ω with about 10mV output-drop and acts similar to above 3 at about 26Ω with 175mV drop e.g. 4.83V output -- though /̲!̲\̲ it does not have thermal protection and it's current limiting is poorly studied /̲!̲\̲