Merging Projects

I've broken my PO project down into chunks - I built the first PHPR to handle CRUD for the look-up tables, manufactures, GL Codes, Shipping Methods, etc.
I then built Item Maintenance as a separate project (easier for me to keep up with the master / detail, etc. in smaller bites and if I have an issue I'm redoing a smaller piece)... I plan on doing the same thing with Vendors>Items, Vendors>Locations, etc.
I'd like to merge them together for the final 'full' application. Save each project as a template and merge? Any tips, gotcha's, etc. anyone can share greatly appreciated!