Using Multiple Taps on Transformer with Shared 0V
Your understanding and approach are correct. The pair of half-wave rectifiers on the 430 V feed means that the ground is correctly and directly connected to the 0 V tap. (The frequent error for novices is to use a full-wave bridge rectifier which separates the 0 V from the DC negative output but your circuit does not fall into this trap.)

Your 60 V output is clearly sharing the same ground as the 430 V circuit so there is no problem there.

Observe the current limit. It is likely that the secondary is all wound with the same gauge of wire so the 0 - 60 V section carries the total current of the 60 V output and the lower 320 V output. (The 320 V winding is only passing current for every second half-cycle so you can take that into your calculations too, if required.)