Posted By: Bill H Thu, Aug 17, 2017
The Chinese language website https://zhidao.baidu.com/question/559431008.html had a query concerning teapots like yours, which received the response I've summed up roughly below from a machine translation:
Concerning the mark "Made under the supervision of Hongfa" (鴻發督造/鸿发督造 - Hongfa du zao), responses included two views, one holding that "Hongfa" was a well-known tea-making company of the late Qing to early Republic era, for which firm some unique tea sets were made with this printed mark and which sets were given as gifts and retained by many in the vicinity of the old factory. The other view held that teapots with this mark were made under the noted Lei Hongfa (雷鴻發), a Republic of China porcelain painter, whose pastel (粉彩 - fencai) porcelain was exceptional, though such works of his are rare and often copied.
I was unable to identify the painter named "Lei Hongfa" but find the version about porcelain tea wares being handed out by the old tea company to be plausible. I located some other porcelains online with the "Hongfa du zao" mark and believe they look like modern copies. Here's one, so you can judge for yourself.