Reading datasheet addresses for base and offsets
The base address 5 hex values ...

The base addresses are four hex digits long. The offsets are two.
Taking SFRRPCR:
0100h = 0x0100 = 0000 0001 0000 0000
+004h = 0x0004 = 0000 0000 0000 0100
                 -------------------
        Sum    = 0000 0001 0000 0100 = 0104h = 0x0104