Congrats on this very special find. I didn't see the auction but WW2 Paramarine items are a bargain at any price.
The jump cert is a great document to have survived with the winged uniforms. Looks like the date on it is 9/11/43. I have a ParaMarine grouping to PFC Holec who graduated from Company B, Para Training School on 12/8/43 and then went to G Co. 2/26 with 5th MarDiv for the invasion of Iwo Jima. Interesting to compare the similarities in service of these two 5th MarDiv ParaMarines.
Here is the group of PFC Holec: