Jimbo Jimbo....   Man that's Harsh stuff !!!   You like to live dangerously don't you!!!  LOL

Lets talk about...  Tamiya grey Putty and Tamiya Lacquer thinner....   for a sec.

If you have those on hand...?

Do a quick test...  NOT on the model  Please !!!!    but on your bench...on some scrap plastic...  and test it out ....  make a small gap you want to fill !!!   for testing purpose sake...

Use "Tamiya" Gray Putty !  and "Tamiya" Lacquer Thinner..   not any other brand Lacquer Thinner...  hence why the TAMIYA is Quoted !!!

It smooths.... super nice and doesn't harm the styrene....   which is surprising!!!  ... but Tamiya knows their stuff! 

Use a small rag or Scott towel and put some Tamiya Lacquer Thinner on it and Wipe off the excess PUTTY while its still Curing...  NOT wet!   but Skinned over.... and Voila !   almost or no sanding required !!!  

I hope this will help you ???