I think I see what you mean, the wing struts and the landing gear struts should probably be thicker?
Well, the struts too...
Sorry mate, but at current stage this drawing doesn't even really qualify as WIP.
1) There are numerous artifacts all around - especially around the struts and undercarriage, but also all over the fuselage;
2) It has no shading except the bottom side of the wings;
3) It has lots of "heavy corners" and even blotches of duble black lines which are the no-no in the style: http://shipbucket.com/styleguide#21
(the Style Guide refers to the SB-scale, but although there are style differences between SB and FD, the FD is derived from SB and that point remains valid in both scales);
4) The main wheel(s)... First of all: they are not circular (in the sense permitted by properties of pixelart) - in other words, if this wheel were to be cut into four parts, none of these parts would match any of the other three. Also, it's all black - and only the contours (outward contour of whole wheel and inside contour dividing the tyre and central metal part) are to be black, while the "color" of the tyre itself ought to be dark grey;
5) Even a passing look on a photograph would tell You that fairing behind the cockpit doesn't create a flat surface with the fuselage, but it's a bulge "standing out" of it;
https://upload.wikimedia.org/wikipedia/ ... ton_DC.jpg
6) Propeller - since it's a two-bladed example, then both blades should have the same shape and thickness;
7) Engine... perhaps I'm wrong, but I believe that the original one wasn't a shapeless lump of "something" - it should have a regular contour all around, including the cyllinders. On the bottom of the picture I've added some examples of properly made radial engines of that era;
8) Last but not least... generally the line separating the vertical stabilizer (and fuselage) from the rudder is marked in black (because there's a clear break in the continuity of the surface) - and that line goes all the way, including that pixel on top You've left out.