I'm trying to order some drum slides, Upper Drum support, felt drum seal and timer for a 15-20 year old GE electric cloths dryer. Contacting GE as well as the owners manual and several sites on the web say the SN/ model number should be on the front case with the door open. There is no tag in this area. I have compared the pictures of the control panel in owners manual with my dryer and figured out it is a DVLR223. Only problem is this is only the base model number and I need the whole number to buy parts. Is there any way to tell what those letters after the base number mean?