I’ve been trying to remember which modelling book I have seen that has the scale drawings for the trailer that is pulled by thr M26 Dragon Wagaon. And yes I know there is a kit out there now, but I have the M26 but no trailer, i’m not buying a whole kit just for the trailer (although you can never have too many exrta models) Anyway I know there is a book that has th drawings in it, is it Shep Paynes How to Build a Diorama? or one of the early Verlinden way books?
Why don’t you try posting a request at some of the other AFV modelling sites’ classified sections requesting the M15 trailer? THere may be others who have built the Pacific cab and not built the trailer. If you aren’t aware of these sites, contact me and I can help you out.
For the expense of getting Paine’s book and the effort at scratchbuidling it yourself, I’d go that route instead. Also the full M26 goes for about $70 on eBay. Why don’t you sell your M26 tractor (probably get $30-35 for it) and then get the full kit? Is your modelling time worth more than the net $30 or so you’d save by not getting the fuller kit?