I recently undertook a very quick project in one morning, on work placement at the ERO, whereby I had to mount two parchment documents for display. The documents had already been cleaned and did not require any further treatment, thus mounting could commence. The objects were measured and mountboard supports cut to an appropriate size for both, in this case they were very similar and were thus kept the same, which also provided aesthetic harmony to the display.
Slits were cut into the mountboard pieces using a chisel and hammer, and thin Melinex strips were inserted though and held in place with Japanese paper tabs and wheat starch paste. The documents were inserted underneath the strips and the mounting was complete. The wax seals did not require extra surrounding support as they were stable enough and not particularly vulnerable.