No you're right, was doing some more reading tonight and even the 9400 is bigger than the 350! And I thought the JVC was big! But it is oriented differently and, luckily only 200g heavier so it can be mounted where the JVC is, but it is another beast!
Occasionally you can get lucky and maybe this is one of those occasions.
It's a very old matt White optima (I think) pull down screen.... Think I got it off here for £40 in the classifieds..... So that might be something else worth looking at upgrading to a grey screen.
Not cheap but the Diverse Screens from @Rickyj at Kalibrate are top notch quality and way better than it's RRP, worthwhile chatting with him on possible options and whilst I wouldn't suggest you would need a Grey screen for a JVC I have found it to be a revelation on the Epson giving it black levels worthy of a dedicated bat cave.