I think so (refer to the text at the very top of the web page). It is almost true as XU4 HJ's are virtually non-existant (I don't think I have ever recorded one) so most cars with the reduced GVW should be Sandmans, so common sense says the late HJ XX7 shared the same placards as XU4 (there should be 3 x reduced GVW HJ tyre placards). Early HJ XX7 are no different to later XU3 or any other commercial with teh same engine and hence should all use the same placard (which appears to be the HQ one).