Should I use LAST Preservative or Uranium 238?

As you read this post, a 12 inch LP, along with a cartridge and needle, are traversing the "termination shock" and soon will enter the heliopause (about 80 AU from us). In an effort to preserve the LP for future Milky Way generations, it was coated with a substance called "Uranium 238", which is said to have a half life of 4.5 billion years. Will "Last" preserve our records for the next 50 to 100 years or should we use an alternative such as U. 238? For details about the Lp and its journey, cut and paste the link below. http://voyager.jpl.nasa.gov/spacecraft/goldenrec.html