“ I believe I bought these tickets before the updated Early Bird rules mentioned by Dutch Traveler went into effect. Would they honor the rules under which I bought them?”
Yes, they specifically stated that the new rules only apply to tickets bought AFTER the new rules came into effect.
“Do tickets purchased under the updated rules restricting use of an “Early Bird” ticket to a specific train show a time on them? If not, is there some code or train number that is used instead and how do I determine what time this is?”
Yes, tickets purchased under the updated rules show the time and date.
“If I am subject to the new rules and there is something on the ticket that indicates the time, how do I get a refund and buy tickets NOW that give me the flexibility to choose whichever departure I want? Can I get a more favorable price for doing so?”
Not applicable to you, because the new rules don’t apply to tickets that were bought before the new fare rule came into effect.