Need help identifying the brand and model number of valve

I am hoping someone can identify from the attached photo the valve and diaphragm for my toro sprinkler system. The system was installed in the early 1990's by the previous owner. I looked on toro site but didn't see this particular of those on the toro site. The valve cover has the number d91 and no other identifying markings that I can see.

Thanks for the help.

Looks like a Toro model 264 series valve. Valve is still available. My experience with them is that they are very reliable.

For the price of the part, install a new valve.. Toro or Hunter etc...They are cheap.