I found the Armegedon kit on the Squadron Mail Order website; it costs $26.97, and the implication is that it's in stock. I haven't seen it, but Squadron says it has a "customer rating" of four stars. The boxtop picture suggests that whoever painted it knew what an LCVP looked like, all right; what that says about the kit contents is anybody's guess.
The Floating Drydock website (<www.floatingdrydock.com>) offers two sets of plans for an LCVP: TFW-LCVP/2 on 1/48 scale for $8.00 and TFW-LCVP/4 on 1/24 scale for $12.00. I imagine they're made from the same original. I have the 1/48 one. I haven't gotten it out to look at for some years (in fact I'm not sure I could find it), but my recollection is that it's a nice piece of work. As I remember it's a single sheet, with three or four views - all external. (There may be a longitudinal cross-section with some internal structural details; I don't recall.) You couldn't build a full-sized LCVP from that drawing. On the other hand, it probably would be more than satisfactory to serve as the basis of a 1/72 scale model, with help from photographs.
My trip to the Squadron site reminded me that Squadron has recently published a paperback book called
U.S. Landing Craft in Action. The books in that series, despite the slightly sensationalized titles, are usually pretty good. They generally contain lots of well-chosen photographs, a few three-view drawings, and some really nice pen-and-ink renderings of perspective details done with the modeler in mind. I don't have a copy of that particular volume, but I'll look for it.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.