It is possible that it will just get fixed. The best deal here for you is if they open a claim, fix the problems and everyone goes on. The only reason I brought up the case of it getting totaled, is because it is a 12 year-old car and it is a possibility you need to be prepared for.
If it is totaled, you can purchase it back from the insurance company before they sell it to a salvage yard. It will have what is called a "salvage title". You and the insurance company will agree upon a buyout for your vehicle and when they pay you, they just bought it from you. If this happens, decide up front, before you settle with them, what you want to do, and at what price you are willing to do it. If you have not yet signed off on their offer to purchase your truck, you have better leverage for your offer to buy it back from them. Remember, that if you buy it back from them, you are buying it as-is, and any repairs will have to come out of the proceeds of the buyout, or your pocket. Go look at other 1999's for sale. Depending on how this goes, it may or may not be a good deal.
Insurance on a salvage title vehicle will be different. You will probably have to shop to find a comprehensive to cover it, and if you do, it will cover it at the same level that you purchased it back. In other words, for not much money.
If they call you and tell you they want to total it, immediately respond that you want it repaired, not totaled. They will be prepared to defend their case and will try to convince you that state laws require this, etc., etc. If they are not willing to comply, be professional, kind and walk away. They will come back to you with their offer again. If they won't comply the second time, walk away again. They will come back again. If they offer to repair it and issue a salvage title, DO NOT ACCEPT! If they won't discuss the third time, then start negotiating your price for the buyout and start deciding if you want to try and keep it or not. You don't have to do all of this while you are on the phone with them. Take all of the numbers, create a spreadsheet, do your research and get back to them when you are comfortable with your decision. Most of all, be patient. Your best results will likely not come from a quick resolution.
For that filter, cmfhsu is correct. Just stab a flat tip screwdriver (bigger is better) right through the middle of that filter. I little wrist twisting might be required to get it all they way through, but once it is, you have the leverage you need.