Analog film photography and cameras

You might know this already...

Printing for exhibition purposes is a slightly different game. Immediately your audience is further away - several paces rather compared with less than arms length - so bigger is generally better, assuming the image is of a suitable quality.

I'd be inclined to scan, photoshop as required (enlargement and cropping at least) and try some variations on hue tone sharpness etc. Print the variations 5x7 / A5 on whatever printer you have access to and then be critical and selective before having expensive 12x18 / A3 prints made.

It might even be worth doing a bit of reading before scanning - much of the logic regarding digital camera settings applies equally to negative scanning, e.g.
http://photography.about.com/od/developingandprinting/ss/howbigcaniprintmyphotos.htm

Apologies if I'm suggesting the obvious - you can always go to https://www.lfgss.com/conversations/187128/ and complain about condescending old gits.