So I backed up many thousands of family photos and hundreds of model train CAD drawings  to an external hard drive. Safe, right?  Of course, several years later the drive failed to connect to the computer (does not matter what operating system, it just failed)

I send it out to a reliable local computer repair.  They tried, then opened up the plastic case (not the HD enclosure), and could not do more.  They very wisely closed it up to prevent more damage.

https://pin.it/jpwexmuijwzgcb

It’s downright amazing what you can find if you look hard enough. There is someone out there who has the basic printings, courtesy of Shapeways, to make an HO scale Reading T-1 4-8-4 if you’re so inclined. There’s even a gearbox cover printing available, although you’ll have to supply your own gears, not to mention motor, wheels, rods, valve gear, etc. All this for the grand total of $567.22 without shipping. My recommendation for drivers is Greenway.