Khansz,
The cut-out is about 3' long, made of a
single piece of
steel u-channel. There isn't a reason that you couldn't extend the length, forward or back. The back end of the trailer is a typical beavertail intended for driving heavy
equipment on. Although the cross-bracing is structural, it wouldn't take much to lengthen the U-channel and replace the cross-bracing.
The major question in the
project is where the center of gravity, aft/fore, not abeam, is of the Tartan. You will want to make sure that is on top of the axles. Once you figure out the COG, you could easily add to the channel forward or back to accommodate the Tartan.
Please let me know if you have any other questions,
Patrick.