The Roden SE5a isn't a bad kit overall. It's two kits, in fact, in Hispano and Viper powered versions. You might say that the worst thing about it is that its appearance may have been a reason for the non-existence of a WNW Viper SE5a - remember, at the time WNW were saying that they wouldn't produce kits of types when decent ones already existed, but a few did come out coincidentally, and unfortunately for Roden (SE5a Hispano, Sopwith Triplane, and DH2).
Anyway, there is one glaring aspect of the Roden kits which must dismay or at the very least puzzle modellers who might otherwise be perfectly happy with the Roden kit, and that is the way the inspection windows are dealt with. It really does seem so strange that Roden opted to represent them with unconvincing decals, especially when it can't have been too difficult to mould a recess to act the part, as WNW did.
Forgive the hamfistedness of what follows. It'd be cheeky to call this a tutorial!

I simply wanted to illustrate my own personal approach, and I'm sure others have solved this problem with more style, and maybe a better idea.
Basically, I've hollowed out the recesses, as you can see in the first pic: