The USAAF version list says changes from the P-47D-23 to the D-25 were Bubble Canopy and flat front windshield, enlarged main fuel tank, 30 gallon water tank, water pump adapter, increased oxygen supply, deletions of provisions for contractor equipment RC-96, type E-15 turbo tachometer to replace type E-13, AN-5773-1 engine gage unit to replace type B-7. Roger Freeman gives the D-23-RE as 9,900 pounds empty, 14,000 pounds gross, the D-25RE as 10,000 and 14,600 pounds.
Looking at the Lancaster fuel tank weight I use 1 pound per imperial gallon capacity as a rule of thumb but of course as we know for a cube 1 unit of volume requires 6 units of area, five units of volume requires 22 units of area and so on.