[W126 Coupe] Jumped Timing Chain

[Pavel]

crew

Bought a 560sec last week with a hole through driverside valve cover so
assumed that timing chain jumped.  Took the valve covers off the tensioner
is toast, guide rails are toast.  Valves seem to be OK did not see any
damage on the cams or rockers.  Could I have lucked out and all I will need
to do is put a new chain and tensioner and guide rails?

Another question on my 560sel the one that likes to blow mysterious white
smoke on de-aceleration once a day or when ever it feels like it with new
heads .  I found out that white smoke is oil my 5 and 6 cylinder spark plug
had oil residue on it.  The oil consumption is about 1 quart every 3000mi 
Ran compression  test was

165 in #1 170 in #2 165 in # 3 165 in # 4
165 in #5 170 in #6 165 in #7  175 in #8

I thought that is respectable compression and the car is very powerful.

So what is causing the white smoke?  I did replace 2 tranny modulators.
Could it be the rings going bad or stuck, inside cylinder walls looked new
when i did heads on it about 10k miles ago

thanks
Pavel
380 sec amg
560sel
300cd
560sec (new and injured)