Wasey,
Here are a couple of reasons I think that people don't want to show their serial numbers;
As a dealer, there have been some people who bought the gun, took the numbered part off of it, then returned it as somethig they didn't want. The dealer, if they did not notice now has a unmatching gun. But then why wouldn't the dealer say, sorry, you swapped parts, no return of money?
An individual is afraid that someone will know what gun they have, i.e. claim it was theirs and thus stolen, that uncle sam would then know what they have or some such paranoid views. Personally, I find it a bit odd, I see people who xx out the serial number, then post pictures of it...
And not to sound too negative, but the vast majority of the people on forums don't share info, pictures, stories or even comment on anything, they simply lurk...
BTW, I am sure that Tom was making a general comment, because you wouldn't need to ship from PA since you live in LA
I would send you my FFL 03 and you would ship the pistol to my house.
Ed