Word or phrase for the poor idea of replacing old with nearly as old

Solution 1:

Perhaps humorously

• "out of the fire and into the frying pan"

A reversal of the usual idiom. It doesn't capture the outdatedness aspect, but does represent substituting a bad situation with something less bad but still unacceptable.

Perhaps your "steam car" to "Model T" idea could work if you have a specific intended audience in mind, who can be expected to be familiar with some specific domain. For instance:

• It's like upgrading from Betamax to VHS, and we're in 2016 already.
• It's like upgrading from Windows 95 to XP, and we're in 2016 already.
• It's like upgrading from a manual typewriter to an electric typewriter when what you really need is a word processor.

However, these might leave millenials mystified if they're part of your audience.

Maybe

• Instead of bringing a knife to a gunfight, you're bringing a sword. Better but still useless.
• It's like upgrading from a donkey to a horse when what you really need is a car.

Not exactly pithy, but it could work if you are delivering your argument verbally rather than in writing.

Solution 2:

I am seriously considering going with one of:

• Replacing Fossilized with Superannuated
• Upgrading from forgotten to merely unsupported
• Updating to only just before the millennium
• Replacing Pterodactyl Pie with Dodo Pie
• Running Up a Down Escalator
• Cashing in tickets for the Ark in exchange for ones for the Titanic

I am, however, inclining towards describing it as "Sisyphean Progress" - denoting a pointless task that is foredoomed by its very nature.

Update & Conclusion

After much thought I have decided to go with referring to it as "Another Maginot Line" - for any that are not familiar with that bit of history the Maginot Line was a French defensive construction that cost a fortune, looked impressive and had been obsolete before construction began so was worse than useless so I think that this captures what I was looking for very well.

Thanks to all of those that contributed.

Solution 3:

Consider harebrained,

(adj.) Having or showing little sense; foolish: a harebrained scheme/idea.

Usage Note: The first recorded use of harebrained dates to 1548. The spelling hairbrained also has a long history, going back to the 1500s when hair was a variant spelling of hare. The hair variant was preserved in Scotland into the 1700s, and as a result it is impossible to tell exactly when people began writing hairbrained in the belief that the word means "having a hair-sized brain" rather than "with no more sense than a hare." While hairbrained continues to be used, the standard spelling of the word is harebrained.

[The Free Dictionary]

Usage example:

Replacing a very obsolete item which is currently causing problems with one that is itself obsolete sounds like a harebrained idea to me