my gote tex valve sheared off from the laird board - I got another from shapers. I thought they were same - but doesn't screw in easy and I don't want to force. I dont have thread gauge or calipers - anyone know if it is same or different tread ? Thanks in advance

They look the same. Hold the threads up against each other and see if the grooves fit into each other. Put some silicone grease on the o-ring to get a good seal without twisting the o-ring.

Thanks - threads mesh together well - I think there slightly different diameter by .5 - 1 mm. Best to to check with thread gauge would be best way

Yeah. New one looks bigger diameter. I would try silicone grease. Might screw in easier. If not & only if it was my board & plug, I would lightly sand down the diameter, wash in fresh water to get rid of any contaminants from the sand paper & plastics & refit until it fits.
If silicone grease is on thread before sanding then wash plug in soapy or detergent water then rinse in fresh water. Remember it's the o ring that seals not the thread.

Had the same problem replacing an original white plug with a Shapers,broke the top off the first one trying to fit it as it was tight. Luckily I bought two, the next one I used silicon grease and also used a bit of araldite on two sides of the plug nut so I wouldn't break that one.Let it harden and checked it still breathed then screwed it in. I think Seajuice is on the money and sanding the plug diameter lightly would have been a better way to go.I also ground down the diameter of the socket I used with a grinder to make that thinner it made it a better fit in the plug recess.