After 40 years of purchasing doubles and other firearms, the sheer volume of junk presented as original is beyond my comprehension.
I have a similar kit and keep my Galazan Pro Bore Gauge in my vehicle for anything that passes initial query.
A light is a must as usually the lighting at these things is dismal.
I do understand that to some dealers, the items are a commodity to be bought and sold with the least amount of effort but when I'm spending my money on an expensive double or other firearm, it's 'Caveat Emptor'!-Richard