15 inch steel wheel measurements

I just upgraded from Small bolt pattern to Big bolt pattern moser axles on my 69 STOCK leaf spring location 8 3/4 differential ... I am going to have Stockton build me Custom Steel wheels .... on 15 x 7 REAR wheel ... what back side offset did you do to clear leaf spring and fender lip.... I will be using 255-60-15 tires....
The replacement Moser Axle flange according to Moser should be in virtually same location as original small bolt pattern axle face flange .. THANKS and happy holidays