Stock does not fit on maverick model 88 20 ga. the stock bolt is way too long even w/ the spacer - ATI Outdoors Shotforce Pistol Grip Shotgun Stock

Before buying this I contacted the seller to make sure this would fit my shotgun. They responded by saying yes and I would not need any special tools or other parts so I bought it. Received mine and got started on it right away. I have a Maverick model 88 20 ga. Lots of problems with this. First of all the stock bolt does not work with this item. The stock bolt is over 5 inches long. So I decided that I would try to make up the difference with flat washers. By first looking at it I thought it may only take about 5 to 7 washers. Boy was I ever wrong. It took 41 flat washers before it would finally tighten down. I finally got the stock to fit but it took 41 flat washers and I did not feel comfortable with that much jury rigging safety wise so I just gave up. First I tried using one of the other spacers (not any of the adapters) but ruined it cause the holes were just too small. So it is damaged. Also when I went to put the recoil pad back on I saw where one of the screws broke off so it too is damaged. I just give up on it all. Also please note that the pistol grip itself is hollow and there is no butt plate on it. I know this item is now damaged so I cannot return it. However I have decided that I would give up on the pistol grip butt stock idea and just put a pistol grip on it. Not what I wanted but what the heck. I emailed the seller and asked if they carry those and if so how much does it cost and does the right size bolt come with it. That was on Nov 18th and still have not heard back from them. I hate losing this much money but not much else I can do. I will say this though. Once I got it jury rigged enough to tighten down it was a very comfortable stock.
Thank you