mr p49, I have just discovered and joined this forum, and, having seen your post, will make this reply my first foray into print here. I have an Elddis Whirlwind, with all necessary manuals and documentation, and can send copies of anything useful if you haven't sourced them from anywhere else yet.
I also have a 1989 Whirlwind with docs, so that is at least 3 of us. I find it good, but have a jobe preventing leaks. Especially when I have used my awning, in the tension it places on the awning rail. But we love our facilities and the 'van. Have never used the shower, except to put the rose thro the window to wash the sand off the kids.
Actually as far as the manuals are concerned, apart from absolute specs like kerb and nose weights I suspect there is not much between them. Having now looked at the original sales brochure which is in my paperwork, the only specified diffference I can see between the internal layouts is the cooker position. Anyway, you never know what's been changed or added in the van's life.