LGC is probably Lydsboro Glass Works that operated in Lyndboro NH off and on from the 1870's to early 1900's. They put out hundreds of named bottles you would recognize.
Actually the letters are 143 LGW, which is likely Lauren's Bottling Works in Lauren, South Carolina. It is not certain, but from the website the number 143 or I43 indicates bottles produced in 1943. The following website gives a good history of the Laurens Bottling Works;
If you ever come across another Plott bottle, please let me know. I am interested - family surname. The Plott hound is the state dog of North Carolina. I just bought this bottle, which was recently listed on eBay. Thanks.