Ok, correction, it was posts by gggGary in the thread 'Friendly Dissagreement about Mixture Screws' that I'd seen before and I've just found it, and it confirms that my float bowls are configured for 30/96 jets. Interestingly, there are two tiny pilot jet holes at the crown of the venturi just in front of the top edge of the throttle plate and a slightly larger mixture screw hole to the side, so these carbs I suspect are the originals for my 73 TX.
