Hey thank you very much HouseElf 
And please steal and copy my paint scheme ofc, you know what they say about imitation! 
I originally planned to put more detailing on all the wings, but I decided the underneath fins weren’t really visible enough to be worth the extra painting time, and with the side wings they are too different on each side so anything I did looked kinda wrong to me. Darn that ramshackle Goblin engineering eh!? 
I even painted various logos onto the wings too, but I ended up painting back over them all anyway as I couldn’t find anything I liked the look of - again, I wanted the wings to look similar on each side if I did that. Maybe a single logo on one side would look okay though.
That’s very strange you had painting issues though. I washed mine with warm soapy water as usual with resin stuff, and then spray undercoated it before painting (as I do with any model). I mostly paint with Vallejo paints but I do use some GW stuff too so that shouldn’t be the cause of your issue really. I suspect it’s not enough washing or something to do with your undercoat most likely?
And yeah assembling any resin or metal kit tends to be more of a challenge if you’re not experienced with them I think than the standard plastic sprues. In general the Mantic stuff I’ve got hasn’t been the easiest at all, but thankfully it’s all within my difficulty level as I’ve got many years of working with really difficult & heavy metal models behind me! I did do a youtube search for how to put the Winggit together though and found an excellent video for that thankfully.
As for the Mincer… here was my saga with that model:
All fine in the end! 
But it was definitely more confusing and more difficult than this Winggit.
Btw there are still ways to get hold of Snotling Pump Wagons. Ofc on ebay etc they tend to be very expensive, but there are some recasters I’ve found that do them… not really legal ofc and I wouldn’t normally even mention that, but as it’s OOP anyway and GW, in this case I would personally find it ok, your mileage may vary of course and that’s fine.