that is some nice lineart you have there! They look pretty awesome
did you know you can colour those with MS paint? the standard programme that's on windows?
it goes like this: you open the scanned file in paint and save it as a "monochrome bitfolder" (in dutch it says "monochrome bitmap" but it's something like that.
after that you re-save it as a 24-bitmap.
Some lines may be "broken", with the black pencil you can fill them up.
After that you can use all existing colours to colour your 24-bit scan.
If you need more info on this matter, just let me know and I'll help you out. It's easy and fun!