SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I am new to this forum but, from what I have read here, the knowledge in great.

I have an old lawn system using Hardie valve. The body has 311A-75 embossed on it.

I understand Irritrol valves have replaced them. Is there an Irritrol "plug replacement" for the Hardie valve? And how do I find its number.

Some of the valves are leaking and either need replacement or new o-rings. Is there a part number or size identifier for O-rings