This endoscope is pretty neat in that it hooks up to your iPhone via WiFi. The pictures posted were exactly the resolution visible on the phone screen. Compared to the naked eye, it was an improvement. For example, the large pit @6" with the naked eye looked no bigger than what turned out to be little pinholes elsewhere. At least a premonition of something larger was apparent with this el-cheapo endoscope. However, I could never achieve satisfactory focus with the 90 degree attachment for a close look.
Mr. Merrington measured the min walls at .027L and .025R. Bores are proofed for BP @.740 (1974) and measure as such. Mr. Merrington believed they were honed and reproofed at the same time.
