No problem!
The Yashica D and 124G are pretty similar. The only differences (I think) are the focusing knob is on the left for 124 and right on the D, the 124 can shoot 220 film, while the D cannot, the 124 has a meter (but it's notoriously bad so it doesn't matter too much) and the D does not. There's probably some other minor differences. If I'm ever between cameras, 9 times out of 10, there's a thread somewhere on the internet conveniently comparing both cameras so I'd try that too.