Yes Massimo, "Za Otradnova" is an attractive scheme but the choice is not particularly inspired on my part. If you want to do a 1:48 single-seat IL-2 that isn't all white it is pretty much the only choice available. Sadly there isn't a lot in the way of after market decals catering to the single seat IL-2 in 1:48.
Hi Robert
if you have to use aftermarket decals!
given that many of the schemes are stars and numbers, and there are profiles on here, it would be pretty easy to make a stencil, or a negative mask to do the numbers
see here for one way -
http://agapemodels.com/2013/02/15/techniques-making-negative-masks/or hand paint onto clear decal film, or just hand paint it, as many were quiet crudely done originally!
eg -
now doing an outlined number would be trickier, but not impossible.
bearing this in mind, I'd have another look through the profile pages and pick one you fancy, and then test the techniques on a scrap kit
HTH
T