How to use #777 Off axis guider with CCD???

I have a #777 Off axis guider (for 35 mm camera use) I want to use the #777 off axis guider with a meade DSI ccd, I think I need a T-Mount extension tube or t mount to
1 1/4" eyepiece adapter to allow the reticle eyepiece to reach focus, has anyone had any experience with doing this?, If so what do I need. I've see meade has a #778 off axis guider for ccd, but I was trying to use the one I already have.

Thanks,
Frank

I ordered a 50mm t-mount extension tube , if anyone has the #778 off axis guider could you please tell me the length of the t-mount extension tube that comes with it, based on photos i've seen it looks pretty close to 50mm.

Thanks,
Frank