pssstt Jeff, they ain't lyin'! but IYO what do they gain by leading you astray?
Go find a 5' or 10' piece of your size galvanized down at Lowe's etc. and lift it. Then calculate say 60' of it. Add the weight of the pump, maybe 50#, the cable and all the rust on and in the pipe. Add the weight of the water in the pipe at 8.4 lb/gallon and say you have 15 gallon. Can you see you and maybe a short skinny guy that can slip in there with you bent over under the roof lifting and HOLDing all that while you realize the pipe may be 20-21' sections held together with rusted threaded couplers that take a pair of 24" pipe wrenches and maybe a torch to get off. All that while the pipe is maybe 6" inside your back wall behind the tank. Okay, add a 2' hole in the roof and that at least allows someone standing on the roof to hold the pipe section that's above the roof but... how did you say you'll HOLD the weight while unscrewing the sections so you don't drop the pump down the well?
And it isn't "if" you have to replace the pump or get into the well to replace a check valve, it's when. And 'when' comes sooner the longer it's been since it was done the last time.
My advice, remove the building allowing free space of at least 5' around the well in all directions. You have to kneel for a fairly long time just to get that sanitary well seal off the casing. Personally I cut two of the four bolts off with a torch and beat the thing and use pry bars... while sweating dropping the pump down the well.
Quality Water Associates