Generic Benroy Plans - need dimension

[Watercamper]

I'm drawing up the Generic Benroy in AutoCAD and I seem to be missing a dimension (or I'm just confused ). Page 15 states that the floor is made from 1/2" Baltic Birch Ply on top of 1 x 2's. I assume of course that these are nominal sizes and that the actual dimensions are 3/4 x 1 1/2. Adding 1 1/2 to 1/2 gives me 2. Page 6 states that the 3/4" walls cover 3 1/8" siderails (of the trailer I assume). So, the dimension from the bottom of the wall to the top of the floor should be 2 + 3 1/8 = 5 1/8. Is this correct?

Page 16 shows the vertical dimension of the aft bulkhead as 4 3/8. Is this dim from the top of the floor? Or, from where is it taken? (the horizontal line isn't defined). I'm trying to get a feel for the correlation between the two dims, 4 3/8 and 5 1/8.

I see the 3 1/8 dim on page 6. Above this top horizontal line for this dim are two more horizontal lines. Can I assume that the first one is 1 1/2 up and the second is 1/2 up? This still doesn't seem to mesh with the 4 3/8 dim. OK - you see my confusion? Can you help me? Thanks!

[KCStudly]

Page 16; I take the bottom line to be the lower edge of the 4 x 8 sheet of 3/4 ply stated to be the side wall. The dimensions are from the bottom and rear edge of the ply before cutting the profile.

The 4-3/8 makes sense if the 1x2's are laid flat. 3-1/8 skirt + 3/4 flat + 1/2 floor skin = 4-3/8

[Watercamper]

Thanks! I knew it would be something simple that I was missing. I looked back at page 15 of the plans and there it is - a nice 1 1/2" horizontal dim which would indicate that the 3/4" is the height! I just had it in my mind that the 1 1/2 " dim was vertical.