Do you mean guide rails, slide rails, or both?

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Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Use of the word rails might have not have been the best choice of words. My meaning was that if the Chain rubs on something with continous contact for 20+ years there must be a wear mark on the part that matches the old Chain. I would not like a new Chain to try to run in the same old groove as the old Chain.
The Long one on the passanger side of the engine (US cars) that the Timing Chain Tensioner pushes against the chain and the Oil Pump has one that pushes on the Oil Pump Drive Chain.
The others should; if possible be looked at but I do not believe that the Chain rubs on them like the big one. (Whe I first got my car I had a noise in the upper Timing Chain area; it was the upper Chain Guid loose.)

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84 300D, 82 Volvo 244Gl Diesel