Hello John,
I also saw your email. Thanks.
I do no think you can do such thing technically. Even if you get the sheet scanned, you will loose the details, sharp lines. To make good quality film you need good drawing ideally in vector format, especially if you plan to enlarge the pattern.
In other words to make sheet from 1:200 to 1:96, you have to really re-draw it.
Another issue is of course copyright story, but that depends on the plate you think of enlarging. But..... when you have plans and you design your own sheet... you can do whatever you want with it.
