Sorry for the delay in getting back to you. It does seem that the website has been slower then normal in posting responses. I wonder if there were some issues the website had to iron out. I will look into it and perhaps send an email to the quality control and IT departments.
However, I do have the info you need. It is listed below.
Freezer door gasket part # pb070292 should cost about $100.
Ref. door gasket part # pb070293 should cost about $105.
Defrost Bi-metal (what you are calling a terminator) part # pr150026 should cost about $87
Circuit Board (no defrost control or timer in your model machine, it simply has a control board that regulates when the unit goes into a defrost and ref cycle) part # pr150005 should cost about $500.
Now if your freezer was icing over and not going into a defrost quick enough or at all and causing excessive ice build up, which is commonly called a defrost failure, the most likely cause and part to fail is the defrost bi-metal. That is the thermostat that sits on the evaporator coil
that is supposed to accurately tell what temp the freezer coils are getting to. And once they get too cold it is supposed to send a signal to the control to tell it to stop the current ref cycle or cooling cycle and put the ref into a defrost cycle. Alot of the time the bi-metal gets water or frost inside and it causes the bi-metal to fail or not accurately judge the temp in the freezer.
If you have a multi meter with a simple continuity check you can check the bimetal to be sure it is good or bad. you would need to access the evaporator and strip or cut the wires to the bimetal with power off to the ref and check the wires of the bimetal. If there is continuity while the bimetal is satisfied, meaning that it is below freezing temp, then it is good. If no continuity then the bimetal is bad. But very important that the bimetal be cold when you check it. A non satisfied, or otherwise warm bimetal will always show that it is open or doesn't have continuity. So please either check the bimetal while it is on the evaporator coil being chilled or cut it out and dip it in some ice water for about ten minutes then check it.
I wouldn't change the circuit board unless you find the bimetal has continuity and is good. The circuit board would be the only other part on this machine that would cause the ref to skip or otherwise not go into a defrost cycle. Unless of course the freezer or ref door gaskets are torn that bad that they are letting int to much warm air. Causing the ref to constantly run giving you the excessive frost and ice. Which I guess may be the reason you also wanted the ref and freezer door gasket info. Unless they are just looking old and worn down and you would like to replace them with the correct parts.
Which leads me to remind you that the parts info I have listed above is the most current and updated part info for your model machine. The door gaskets are the same door gaskets that you have in your machine now. they have a lip that gets held down by the trim that goes around the door frame. Not the push in kind that just fit into the groove like you have previously received. And all of these parts were indeed checked by the authorized Viking parts department reps. Which they did also tell me that most of these parts are not currently in stock but are able to be ordered. Which just simple means that due to the age of the machine, their normal warehouses dont have any left and it needs to come from the main warehouse. Which usually takes about 5-10 business days to come in. Thats all.
You can either call Viking directly to order the parts or use www.allvikingparts.com and pay almost double the price or use the phone number and website below that I use regularly. The info below is to a company I have been using for years and is the single biggest appliance parts distributor in the country. They offer a better return and warranty policy then any other parts warehouse out there now. And best part about it is that they will give you the factory original and authorized oem part as would Viking. The get discounted prices because of the volume of business they do. You are essentially getting the parts at a wholesale and not a retail rate. You just need to make sure you either use the phone number below or log into their website through my portal to be sure you get the biggest discount as possible.
Parts warehouse info:
Long Island Appliance Associates/ Marcone Appliance Parts
Phone: 1-877-821-4170 ( can be on hold a little while, but when an operator answers just give them the part numbers above and they will give you the part info and send it out to you quickly)
If you dont want to wait on the phone, fi they are busy which happens often, then just log into the website at www.applianceassociatesli.com and go to the parts link at the top of the page. When the parts portal page opens just enter the part numbers into the part search box and the parts info will populate. Just order the parts from there to save time.
Please get back to me here if you have any other questions or concerns with either ordering or installing the parts and I will help you more for no additional charge.
Thanks again for the positive rating. Please also get back to me and let me know how you make out with the repair.