Here are some reports/documents on Jack Lawrence which I found:
This is an interesting article on Lawrence by someone named Sheldon Inkol:
I’m interested in knowing what you guys think of Lawrence. Of note to me is that Lawrence checked in to the YMCA in Dallas on October 6, 1963. This was a mere three days after someone claiming to be Oswald checked in to the YMCA; and just one day after the show “How Hollywood Makes Movies” (which Ruby was evidently involved with) opened at the Dallas Fairgrounds. As I discussed in the “Crafard Puzzle” thread, there is reason to believe that illegal gun running activities were taking place at the Fairgrounds. See the following links:
Returning now to the YMCA, Jack Ruby was said to frequent the YMCA’s health club. On October 17, 1963, Loran Hall and Lawrence Howard (both of whom were involved in activities against Castro including gun running) checked into the YMCA at Dallas. However, Howard denied this. Several employees and residents of the YMCA were also questioned about a “group of Cubans” at the YMCA. See the following links:
If you click on the very first link in this thread, you will see that Jack Lawrence claimed to have been connected to the National Aeronautical Space Agency in St Petersburg, Florida (this was almost certainly a reference to NASA). Some of you may recall that several employees of the Reily Coffee Company (where Oswald worked from May 10, 1963 to July 19, 1963) went on to work for NASA. Lawrence was allegedly unemployed from sometime in January, 1963 to sometime in May, 1963; and was apparently living in St Petersburg Florida during this period of time (see the second link in this thread). I don’t know how significant this information is, but I think it’s something to keep in mind.