and yes if you give me a 3D printer capable of printing something as wide as an A1200 I will hand you a case in 24 hours....the 0ther 24 hours is to print the custom lids for a 64C and A1200 
Not necessarilly! An A1200 can be literally cut down in width to fit in an A600 case. No, that's no joke, and it's already been done. So that's not the problem. User Jimbob from Amibay has proven so:

And here's his thread:
http://www.amibay.com/showthread.php?t=570Nothing's impossible. I always thought of having a SAM mobo and turning it into a good-looking laptop, but have found no donors..

Don't rush into saying i'm just 'all talk and no play', i'm proud to have built a portable A600 meself:

Yes, it's feasible. Took me more than a grand of Euros, but it was well worth it.
http://www.amigahellas.gr/showthread.php?5166-A600-GRL-projectI think i mentioned this A600 sometime ago, but just in case...