hylomar

Just about to pull the top end and replace pushrod tube seals. My tube of Wurth DP300, which Oak said was the same as Hylomar, is 10 years old. While it appears to be good, the shelf life (according to the internet) is only 60 months. It appears Wurth DP 300 is no longer available in the US...

Anyone know where I can buy hylomar sealant or if there is something out there that is basically the same features?