1315 was actually 1311/411 and they are basically close in factory builds. 1313 did come with air cleaners, but by summer, it seems all the early LAH tigers had them removed, damage??, so the "Y" fitting should be there. The deck layout should look like mine. BTW, from pictures there is another one of these early ones 1324, I think?? have to look at my pics, but am at work, and I think 1312 is, but hard to see if the side skirts slope.
But anyway, you can base 1313 off my build. I was actually going to build it, but had more info on 1311/411.