Joe Blowe, you think the way I do... I have taken half a dozen tanks off vehicles and really cleaned them up ... Always felt better about them afterwards...and found a lot of stuff inside some of them.... some were even starting to rust on the top outside.... I treated it just like it was the hood... some mechanic will see that and think someone was compulsive/obsessive.... .... but I know it will last another 20 years...Take pics if you do it for the FAQ pages , if they are still around... many people OUGHT to clean their 20+ year old tanks but don't tackle it.... if you do flush it... how about emptying it through cheesecloth for picture taking purposes.... some might be surprised at what you find....