tactical rear stock for 1100LW, 20 guage

[Virginian]

Read this:
http://www.remingtonsociety.com/rsa/journals/1100

The original 20 gauges were built on the 12 gauge sized receiver. The LW and LT are both smaller sized receivers, and hence stocks will not interchange without modification. Unfortunately, as you have discovered, not everyone who calls themselves a gunsmith these days is one.