I'm not familiar with the table you have but if it's an old table made in the USA it's most likely a K55 profile. The rubber that Bob Jewett mentioned is European 4 sided rubber.
Not having a table mechanic isn't around isn't the end of the world. I gave my rails to a master cabnet maker with a sample of the liner I needed. I thought he'd simply make me a new liner and cut off the old, but instead he built a jig, set up his knives and cut the existing liner warped rail and all. No problem. Came out great. Cost about $300 for the mod. and around $300 for the rubber 15 years ago.