The ohm rating of the transformer in the program is not the resistance but the impedance. There is an impedance calculator in the program that uses measured input (wall) voltage, resistance of the primary and secondary winding of the transformer and the unloaded voltage output.

When you right click on the tranformer in the program to edit, both parameters have a button after the data entry box with "..." in them. Click on the resistance box and it will help you calculate impedance.

The current tap ratings were a guess based on tube ratings. At some point I will measure the current draw of the small signal tube and subtract that from the total 80mA of current draw.

You are of course right about the capacitors in series.

Is the R core transformer 250 center tapped, i.e. 250-0-250?