Firstly, Luftwaffe sleeve rank gulls - were they worn on both sleeves? Brian Davis' book is surprisingly quiet on that question - although there are pics of FJ wearing them on the Knockensack. 
Secondly, would a FJ Unteroffizier have tresse on his Fliegerbluse shoulderboards or just around the collar?
Thirdly, what's the best method of sewing on tresse? i.e. how do you do corners? Do you cut it into separate strips, or "bend" it, or what?
Fourthly, was the infantry assault badge awarded to officers as well as EM ?
You've got nothing to ein, zwei, drei, vier
You mean on knochensack ? if so yes, if not no
....er... to question 1 ??
You've got nothing to ein, zwei, drei, vier
Sorry yes Q1
Q2 when I did Carls orifacer tunic, the shoulder boards already had tress on them but not in the way I think you mean 
so I don't really get what you mean by that, what rank you doing ? but yes it had it on the collars as well.
Q3 I found it easier doing tress with a sewing maching and folded it over in the corners and just ran 2 rows of running stitches up each side
Q4 no idea,but will have a look later, I assume it must be possible they have been awarded it, after all they may have received it whislt a junior rank/EM, but no idea if an orifacer had been awarded one, though I don't see any reason why not, but thats just me thinking not fact (before anyone comments, I'm merely thinking aloud/as I type).
Andy - to clarify your Luftwaffe Unteroffizier Rank and question about Tresse:-
BLD's U&IotL Vol 2 page 40 -ref 121 & 122 - you can see that you'll need Collar Tresse and Shoulderboard Tresse and appropriate waffenfarbe as well as collar waffenfarbe and 1 gull.
Look at same volume by BLD pages 133 - 136 regarding the Rank Insignia for Flight Clothing
See i wasn't sure if he was modding some EM shoulder boards with tress himself 
cos most people buy them in a suitable rank completed, so I'm bemused to know why he asking 
Cheers for the info, both of you. Well... you know how one thing leads to another.... Boshman sent me some arm rank gulls, equivalent to LW Unteroffizier. I understand that other units like FJ used to poach these and use them on camo uniforms. So, with my Fliegerbluse already having one collar tab gull, all I needed to promote myself to Unteroffizier is some tresse. So, yes, I will be attempting to sew it onto the s/boards as well.... 
"Frau Steiner...! Wo bist du, meine Liebling..?" 
You've got nothing to ein, zwei, drei, vier
See you could have just explained that at the beginning and it would instantly have made more sense, Frau Steiner has obviously done the right thing, and left you to it, so she can return and laugh at your attempts
One arm gull done - took less than an hour! 
You've got nothing to ein, zwei, drei, vier
