The RENE lists the serial number range for all Lightweights is as follows;
1956, 200000,,, until 1959,, and 212534.
So,, apparently,, yes is should be a LWT.
Check the cylinder with a magnet. It's in the right general serial number range to be a "steel cylinder lightweight" variation. Kinda looks like it. :wink:
I once did something similar. At a gun show,, friday night after set-up,, wandering the tables. Spotted the different coloration of the gun from about 15 ft away. Asked about seeing it,, immediately recognized it as a LWT, and asked the price. Was happy to pay $325 back then. You beat my price,,!!