a plumber cut a 2 x 4' access clean out in a 3.5' iron roof drain pipe. The pipe is in the corner of a basement kitchen. He covered it with some duct tape. I did a fiberglass tape repair but looking for a more permanent fix. I have used what I call a saddle clamp (metal plate with a tie bracket bolting it together) found many for 6' & one 2' clamps any ideas?

I'm trying to understand your complaint.
You say a plumber cut in a 2" clean out in a 3 1/2" pipe that carries rain water to your sewer and simply duct taped the connections? And you paid him to do this?
What material are the pipes?
You ask;
I'm ooking for a more permanent fix.
Without more details the best I can come up[ with 8is No-Hub Bands, (see image) Good luck. Tom

Cast iron, installed in 1923

If there are no hubs involved then No-Hub Bands should replace the duct tape and fiberglass. Good luck, Tom

If the "no hub clamps" can be opened then I can get them around the pipe else no. The metal clamp bands are not the concern they open but does the gasket and other supporting elements do they open?

While the No-Hub Bands can be opened the fitting will have to be able to accept the Neoprene gaskets that will seal the joints.
Simply take a raiser clamp and bumper jack to lift the pipe off the fitting and slip the gaskets in. Good luck, Tom