Doing prep work prior to working on a Spit Mk.Vb. 2 options I am considering are EP200 (Castle Bromwich , 5-42 build) and EP691 (Castle Bromwich, 7-42 build). Confirmation: Interior armored glass windscreen and bubble , "balloon type sliding hood". Photos of the two I've seen, I'm pretty confident on the windscreen, canopy, not so much. Few photos I've found almost look like flat sided. ("balloon type sliding hood" came in in 41, so "should be"...) And, actual question... IFF "cheese cutters"??? Yes? No? Maybe? One photo of 200 looks like, maybe, an antennae wire. But other photos of both, I dont see the insulator on the fuselage. Also, I know the Brits were paranoid about sending "secret tech" overseas. (took them 3 year to even send Spits to Malta!) Yanked radar out of Mossies used for intruder missions over the continent early on lest the Germans get ahold of one...