I don’t know anything about helmet plates or HPCs but just an observation I’d agree with the other comments about quality. The casting of the oak wreath looks positively shoddy and the detail on the crown isn’t convincing.
I’d also ask, how does this badge fit into the evolution of the design. Look at this thread
https://www.britishbadgeforum.com/fo...ad.php?t=39463 the badge has a KC yet retains the regimental castle. So how/why is it a QVC plate has a regimental castle centre?
Perhaps others more informed than I can answer this but seems at best an oddity a later badge reverting to the earlier castle or perhaps it’s just plain suspicious.