Re: Chama Steam engine placement *PIC*

John, I know I've seen shots of mid-engine helpers on the line in the later years, but I can't for the life of me recall where.
As for the question of what should be done, I'll modify what several others have said from it's what the charter organizer wants that counts to, it's what'll bring paying customers to the event that counts.
While I'm a big proponent of historical operation, from a practical point of view there may be issues that'll force an organizer to make certain tradeoffs. In your example, having a pusher ahead of the caboose is great, IF runbys can be organized which allow good "longview" shots, and that's tough to do. Sure some chasers may be able to get some, but if the folks paying the bills can't, that's a problem. If virtually all runbys will be close to medium distance, then I'm all for using a somewhat less common, but more visually appealing arrangement to satisfy the paying customer.
What Jay put together does appear to have some precedent, and made for a visually appealing, yet workable, consist. Most importantly from the event's point of view, folks seemed to like it.
And while I don't want to open the "when does history end" can of worms, there's even precedent from the C&TS in a working (ie non-charter) situation. Recall in '04, that the first two loco train since the RR'd been down to one, involved what was really a mid-train helper. Crews needed to spot 4 flats on top of Cumbres, and this arrangement was the easiest way to accomplish that task. Made for an interesting train that day too.
Scott