Just my .02 but I don't think a motorcycle is a good "money investment", especially in the short term. Nine or 10 years is not a long time for collectables.
It's all a matter of supply and demand and H-D really didn't limit the anniversary models (didn't they have a 14 month production run for 2003?) so everyone who wanted an anniversary model got one.
As a buyer with limited funds, like most Harley purchasers they would think about "why would they pay new prices for a 9 year old bike with less features and no warranty?"
You would have to find a buyer who wants a collectable to add to his collection or someone who is just in love with that color and style.
You mentioned that you had all the stock parts, that might appeal to a collector in about 20 or more years, by then many of the 2003 models will have been wrecked, rusted out or highly modified. Then you could find a collector who would love to "find" a near mint 2003 to restore.
To be a true collectable there needs to be a small run of an item, just imagine if H-D only made 100 anniversary bikes in 2003. Then the demand would be much higher.
This is one area that I fell H-D has hurt the "investment" in a CVO since the early days they had small productions of one or two models and for only two years in a row. Look at it now when a CVO is in 3 or 4 models and 3 colors each. You also have the CVO Ultra which has been produced for many years in a row.