Scr power controler. Help

[johnnyH]

Hi. I am trying to resurrect a Pool chlorinator. I have the centre tapped transformer and and the power board which has 2 scr's and myriad unwanted circuitry. The SCR's are JIE  JCT6055/8055 series. Vdrm 600V .It rms 55A and Igt = 10-50mA. I am trying to make a simple regulated supply for the chlorinator plates. I do not need all the control gear ie. timer , reversing , low salt etc. I have come up with what I think would work however I am unable to work out the values of the resistors, capacitors and diodes. also I'm not sure weather to use diodes D3 and D4 to bridge as shown in the drawing.  can anyone help me with the values and indeed if they think it will work satisfactorily. any suggestions would be much appreciated. Diagram attached.