How difficult to build flashlight?

Well, I just got a the Ultrafire XPG flashlight from bestofferbuys, which I believe is the same one sold at kaidomain and dealextreme. They actually sent me a Q5, but then sent me the XPG and its reflector for free. Well, the Q5 bubble covering the led is quite large compared to the XPG, but fits well with the reflector with the large opening. The reflector that they sold for the XPG is not so good. The bubble is behind the reflector and I feel that it is partially blocking the led. Compared to the Q5, the XPG seems slightly less bright and has an outer ring outside the dimmer circle. So my question is two-fold:

Are there any cheap reflectors I can buy that would fit a WF-501B housing?

So they sent you the wrong flashlight, then to correct this error they sent you a bare emitter and reflecter so you can fix this problem yourself?

they sent me a drop in.

Edit:
Original Mistaken Q5


"Corrected" XPG Shipped from China

bumpildy bump

The XP-G has a larger die, so the hotspot would be wider then with a XR-E, which could make the XP-G seem dimmer. The drive current could also be different, which will change the output.

If it's a P60 type drop-in, then there are some P60 drop-in kits that should work.