Your idea has a lot of merit, however, the cost may be prohibitive and may be the reason there is not any existing proof. I would be willing to contribute, but would want to be one of many and to be able to verify use of funds.
I have been to the Citizen's library in Washington, PA and the Cornerstone Genealogical Society in Waynesburg.First trip in Nov. 1998 and second trip in Jul. 2000.I have thoroughly looked through all of the Iams material and can say that the documentation of any court record regarding William Iiams' parentage does not exist in these two locations.
The Elisha Iams research is at the Citizen's library in Washington and fills many volumes.It is not indexed and consists mostly of letters from many sources that he received while doing his research.It would be very strange for the documentation to be hidden in this research.
There are online searches that may be requested in Cornwall, England.I have tried a few of these on the Iiams, I'ans spelling, but to no avail.
I agree with the premise that until there is documented proof for all to see, any conclusion should be put forward with a disclaimer to that effect.
On a side note and in the same line...I have yet to see any documented proof that Richard (first immagrant to Pennsylvania) was the son of John (and who was John's wife) and that John was the son of Richard...I have read all of Anne Arundel County, Iams of America, and other oft quoted sources.
Keep in mind that the journey and the search is most of the fun anyway...