Nad c 552 lp stuck on spindle


Hi, so i am currently looking for a used turntable and i found one on a listing. It's a NAD 552 equipped with OM 10 cartridge. It's in mint condition but there's a twist. The top of the platter has been "shimmed" with a layer of bitumen material (car insulation/dynamat) to heighten the platter. Seller told me if he didn't apply the layer plus the slipmat, the LP would get stuck in the spindle due to the platter sitting too low(???) and he did that years ago and didn't know any other fix. He also told me he received a very thick rubber mat with the tt from the store he bought it from as the standar platter "shim" and he quickly replaced the rubber mat because he thought bitumen works wonder for reducing vibration from the motor. From what i found on the Internet, all NAD C552 turntable never have that kind of issue, no shimming required and of course it only comes with felt mat. My question is ; can i return the NAD tt back to it's standard OEM (remove the ugly bitumen layer and put LP without it getting stuck on the spindle) is this because of the subplatter being too high or low? And is it adjustable? I really like the turntable and its fairly cheap, if it's fixable i would certainly buy this from the seller. Thank you and sorry for my english
daviddjin
Not to knock your pick, but the one I found on YT is so cheap the whole platter wobbles up and down as it turns. https://www.youtube.com/watch?v=NdrgxIs-JSw We have had this before on here, not this exact turntable but others of the same level of build quality. When the platter is stamped like these the metal is very thin and even slight mishandling can be enough to warp - and then it is pretty much impossible to flatten, and costs as much as the table to replace. So this will be a concern, but put it in perspective, this is a concern with every table around this price point.  

Record holes vary a bit. Some fit the spindle a little loose, some are a tight fit. But the spindles, whatever size they are, they are the same diameter the whole way. I have never heard of a tapered spindle. So probably your seller had a couple records that were snug and thought the "fix" is to raise the whole thing up to where the spindle barely goes in the hole. Dunno, but a pretty good guess. I would ask, when playing a record how much of the straight part of the spindle sticks out above the record? If none then you have your answer.
Next I would ask if when playing a record does the platter stay nice and flat or does it wobble like the one in the video? Show him the video so he knows what you mean. 

If it is flat then you are getting basically the original table plus some stuff to try. You may or may not like it, but I would consider it a plus. Except for the purposes of negotiating the price, in that case you would let him know gee sorry but with all the mods you made I can't be sure something isn't messed up and make him a little bit lower offer. Because until you get it and see it could well be true that he did mess it up. So that is the way I would play it. 
Thank you for the reply. Someone offered me an audio technica lp120. What do you think of it compared to the NAD turntable?