I've seen covers with 'Tintin in the Orient Vol 1' or 'Vol 2' and some covers without those and the font colour of the title is different, too. Is there any difference?
I can't say for certain, but I don't think the covers showing the "Orient" line ever made it into production, or ever were released generally - I think that they may have been mock-ups used in advertising to announce the coming of the facsimiles (and to solicit sales from bookshops in advance, which helps estimate how many copies should be printed).
This isn't at all unusual in the book trade, and cover designs are often changed between pre-publication and the final book gets into the hands of the reader.
I've dug around on line, and haven't come across any photos of actual physical books showing the "Orient" line, only "static" pictures of the design as an image file, although that some might exist isn't impossible, as dummy books can be made for use at book-fairs and other publicity events.
For example, at least a couple of early copies of the colour Tintin in the Congo
have been found that are completely textless (the covers have no titles, and the balloons are blank), which were made for Casterman salespeople to show potential clients.
Another example of a similar discrepency is the "Tintin and The Broken Ear" cover image, which was used for years (may still be around, I haven't bought a new book in a long time) in publicity, including in the back-cover gallery of albums, when the book that people got is in fact simply called The Broken Ear
on the cover (although spines may say Tintin and The Broken Ear
Still, I'm happy to be immediately proved wrong, and for people to pop up with their "Orient" copies, but I've not seen one myself, as far as I can recall. So not a definite answer, but the best I can do!