I doubt that paper-tape mold is suitable for papier-mache modelling paste, because of high water content. It will soak paper tape and glue up and whole thing would fall apart.

I'd better give a try to duct-tape, which takes no water in (and adhesive tolerates water as well). Nevertheless, you would like to have precise tool for your future fitting, but duct tape shell would be too thin and soft to support quite heavy load of paper pulp, there is too big risk for distortion (considering that you have to halve the shell). Duct tape is watertight and exess humidity cannot evaporate, making drying time much longer.

Plaster mold would give best support and it tolerates water. It inhibits exess water from pulp and enables evaporation. This time it's best for purpose.