Firstly, don't slap on vaseline.  Cling film is best in my experience because it won't stick to the original and can (with hope and a prayer) be pulled off the inside of the laminate form.
If you can make it work, it is a good idea to place the first layer of the paper over the clingfilm as wet paper, with no paste between it and the clingfilm.  Brush paste (or use your finger) over the outer face and put the next layer on as quickly as possible.  Then build up about six strong layers.   You can do this through holes as well as long as they are large enough to work in.   
Cut through the laminate with a very sharp knife wherever it is needed to release it.  Pull out the clingfilm carefully (if you actually need to!), trying not to distort the laminate any more than you have to.  Join the sections.   I find that spreading a spirit glue works well, sometimes needing to place spots of hot glue to give instant impact at key points.
Apply more layers, sanding and smoothing any visible joints until you have the result you want.
Tip:  this would be extremely light.  If you want to give it bottom weight, glue in a package of sand, or a stone or even a (well sealed!!) small bottle of water.
Good luck
DavidO

All David's advice is good. Most adhesives don't stick to cling film UNLESS you leave unfastened folds, and the paper and/or adhesive gets caught in the folds and dries. If you want to make sure the adhesive you're using won't stick, just lay some film on a table or counter and use your adhesive to glue a piece of paper to it and let it dry. Does it peel off well enough for your purposes?

If your original is made from air-dried clay and is expendable, I would wrap the whole thing in thin plastic, working through the hole and wrapping it like a doughnut, fastening it with water-resistant tape.  Then apply strips of PM with your adhesive until the whole piece is covered with at least four layers. Let dry thoroughly. Then use an Exacto or craft knife to cut inside the hole and around the entire outside so you end up with two halves. Then fasten them together with more PM strips .

If the original is NOT expendable and you don't want to cut on it:

Wrap the entire piece in plastic as above. Then I would take a permanent felt-tip marker and carefully draw a line where you would make a seam, on the outside of the object and inside the hole.

Then apply your strips of PM, starting right along the edge of the line, covering only one side at a time. If gravity is an issue, laying the original on it's side should help. Just make sure that the whole PM section can be lifted off when dry. If there are many undercuts that will trap the PM and make it difficult or impossible to lift off when dry, you may have to do it in more than two sections.

Then do the opposite side the same way. When both halves are done and dry, lift them off and fasten them in place together with more strips of PM.

If you don't understand what I mean, let me know and I'll try to make it more simple.

Sue