My goodness, this has to be a reissue!  I remember talking the neighbor into giving me this unbuilt kit when I was about 12 or so.  It was way oversimplified and the sprues were not completely molded so some parts were incomplete.  What references are you using and how accurate do you want it to be?

HR Products (http://www.hrprod.com) has a number of 1:256 items that would be useful in turning this kit into more of a scale model, including 40mm twins, 20mm singles, floater nets, LCVP's, inclined ladder sections, and life rafts.  I ordered a number of them to detail Lindberg's 1:256 LSD and the fittings are pretty good, nicely cast with only a small amount of flash.  I recall that Scale Ship Modeler (now out of print) published an article on detailing this kit - if Challenge Publications is still in business you should be able to order a reprint.

Good luck with the build.

Mike

I would use 1/250 scale photo-etch for this kit, whatever you can find as there is nothing made specifically for it. Seconded on the GHQ info. Could add some tanks and jeeps exiting the craft. Luckily there is current reference materials on the LST since those veterans went to Greece and returned with a functioning LST. I think it was LST-325

Ah yes it was: www.lstmemorial.org/.../history.html

Not sure what you can find for this odd scale, but you may look at wargaming pieces.  There was one company (GHQ???) that made a series of armor, jeeps, and even Vietnam era riverine craft in 1/285 scale.   At one time I looked at there products for making a diorama of a PBR support LST in Vietnam.  Gold Medal models may have some odd box scale photoetch for another kit that might provide some handrail material.  Good luck!