Excellent work on the engine Jacek!
I too built the German version a few years ago, and found the instructions a little small, although very comprehensive! I actually never finished the model completely as I didn't add a few of the peripheral bits but the airframe was complete.
I put the lozenge decals and rib tapes on to kill time whilst on a 36+ hour train trip between Kansas City and LA, but that's another story and not for this thread!
Looking forward to the rest of the build, I seem to remember the kit was quite good quality with loads of PE..