I have also heard the rumour about the 1/24 Gladiator. It was said to be on the cards when the Mossie was first ‘under development’ in the 70's. However, unlike the Mosquito kit, I can find no mention of it in Arthur Ward’s book, ‘Airfix, Celebrating 50 Years of the Greatest Plastic Kits in the World’.
Whether it will ever be resurrected is another matter. Like you I would love to see one. Hopefully, if the Mossie is successful we may see some additions to the range, what about a Typhoon?