Here are two items posted from Bridgwater that have Postage Due marks.
Firstly here is one from August 1873 with a large 2d handstamp, applied in Bridgwater, with a small "CH" in a circle which was an Inspector's mark applied in Bristol. The postage due was because the envelope was unfranked.
This second item is from October 1904 and is a postcard with glitter. This meant that it was liable to the letter rate and had 1d postage due. It received a framed "CONTRARY TO REGULATION" cachet and a large 1d, both applied in Bridgwater, and a small "CH" in a circle which was an Inspector's mark applied in Bristol.