Merging 2 Drawing's Into One? Can You Tell?

I have drawing's from my drawing books. These drawing's go together. I finally took all the pages out of my books and am going over them and scanning each page individually.I have put these type's of thing's on other pod's but only by scanning the drawing book its self or taking photographs of the whole. Both are not ideal as photograph's still obscure the place where a drawing book is fixed. Taking the book apart was rather liberating as now I can store the pages in a folder or binder and take them out as need be. Any how back to the question at hand the scanning. I feel that scanning these image's is best as they would yield the highest quality print's. I have started scanning them at 1200 PPI(it seems overkill and I downsize them drastically so may try 600PPI ) I scan them individually and then attempt to merge them in Photoshop but this is where some issues can happen. In the past on other pod's I simply thought the look of a book was sort of interesting and left them after some use of stamping. But I wish for a nice clean look where you can not tell it was 2 image's but where it looks like one finished work. This will also be good for later as I plan on painting digital over some of these drawing's and don't wish for the best drawing under them.(plan on also perhaps painting some of the idea's as well)
So I am trying to merge the images as good and seamlessly as possible. I have used the stamp tool, Healing brush,spot healing sharpening tool as I find the grain is never perfect between the images,I use doge and the burn tool to try to capture the same look on both side's. smudging tool sometime's and bluer tool. I can still sort of notice slightly but don't know that is just because being the creator I know the magicians tricks((magicians tricks a good name for a indie band or metal band) and can see the person behind the cloak and it's all in my mind so was wondering if you could tell looking at these that they where merged. All the merging happens in the middle.

Something else I notice and I have no idea why but perhaps the fact I am doing this at 1200 PPI. Sometime's there is a bit of bluing on parts of the image. I will go back and resharpen it but I don't understand why this is happening. I put book's on top of the scanner. So I am noticing a few parts of the image being out of focus but don't get why.Could it be because of vibrations like me being in the same room on the computer desk and perhaps the slight movement's of the keyboard and shaking of the computer desk perhaps shaking the scanner? I have the scanner on the floor. I put a book or so on top so that the lid of the scanner is shut and I also put a book or paint cans on top of the scanner lid so it stay's closed and no light get's to the scanner.

I am also wondering if there is a easier way to merge images more smart. I have Photoshop cs5 but it seems sometimes I am working 2 hour's to get thing's ,merged and looking good before they would be at the level they need to be.








So questions are can you notice they where merged. If you can tell dose it distract from the work, what tool's do you use for this sort of process. Looking at these images again also should I work on the background clarity. I notice that there are smudges and such on the images. I personally don't mind about the smudges as they are on the true work although then again they where not there when I did them originally as I assume they smudged from time. So keep the smudges/dirty marks or try to remove them?(not sure specifically if I can remove them currently but perhaps should try)


So those are all the questions right now, any how thank's for reading all this.