I didn't find some just now, I am saying I have a pair of NOS latches and handles I bought for my 48 on eBay. I then bought a pair more of 53ish because I am thinking about changing them.
Point being they ARE there....but not every day. I did just find this one for the later suburban.
http://www.ebay.com/itm/NOS-55-56-57...BYa8EH&vxp=mtr
Here are NOS strikers for your truck.
http://www.ebay.com/itm/NOS-1952-196...VYn1ld&vxp=mtr
Here is a Right latch.
http://www.ebay.com/itm/1955-1959-Ch...pYuDOX&vxp=mtr
Here is how I find stuff I want on ebay. I make a search with a pretty liberal search words.
1956 Chevy truck door For instance, I do this in "advanced search" go to the bottom of the page to "Sort By" and put it on "TIME: Newly listed" this way I see what was the latest listed, going back to oldest. I check this every morning and find stuff EVERY TIME in a few days or weeks that has a good buy it now price or something and I get it. I will have a crap load of these searches saved to my favorites with all the different years, calling it a truck or a pickup, that sort of thing, I look at them all every morning, in only takes a few seconds being they are the newest listed and you saw the older ones yesterday.
I have found CRAP LOADS of stuff that way, NOS distributor, NOS Corvette 235 Intake, NOS latches, mouldings, headlamp rings, lights, Steering wheel, horn button, brake parts, etc. there is a lot of stuff out there!
Brian