The Red Vestment came with the Statue...
Six Inches...
The Statue is six inches tall and looks like this without the vestment on.
The Red Vestment...
The best way to figure out how to make a vestment seems to be to properly investigate the original. I took apart some stitches and studied it. The span of this vestment is about 10 inches, including the lace.
Some Vocabulary...
Cape - This is the red sides, and around the back. This can be a separate piece, or connected to the vestment.
Vestment - This is the white part, which is under the cape and visible in the front.
Sleeves - This are more like hand-holes on a small statue, covered in lace. The left-hand holds the globe, so the hole has to be considerably larger and slightly lower than the right hand.
Collar - There is a front lacy colar under his chin, and the back collar is sometimes more like a head-rest (the top red fabric with lace)
Alb - is a white undergarment that may have lace on the bottom. For small statues, it is implied by the lace on the bottom of the vestment.
This is what it looks like on the inside...
This vestment has three pieces of fabric: The white vestment, the red cape, with the red collar inner piece. The vestment and cape are half-ovals (which is not pictured here because of some sewing). The head-hole has a slight indentation into the white for the statue's chin. The red goes us into an house shape, that is sewn to the inner red collar piece, and sew the lace so that it sticks out the seam. Lace is sewn down the seam between the red and white to give edging to the cape, making it appear separate. Then sew lace around the bottom edge of the whole oval. The front collar has some folded-down lace. Then try the vestment on the statue to find the position for the hand holes, and round them with lace. Decorations can be added.