Help with 340 compression + cam change

I finally got the snow cleared away from my shop doors and did the compression test with a new gauge (which agreed exactly with my old one.) Engine fully warmed up to about 150-160 degrees, carb open, etc.

I had stated I had 160# all around, well I checked and my last reading was THREE YEARS AGO! Time flies when you're having fun! So with at least 40 runs down the strip since, and "daily driver" duty part time, etc. the #s are as follows:

Four cylinders were still between 158# to 160# (...checked with both gauges)
Three cylinders were 150-155# and number 7 was reading at 145-147#s.

So in spite of the 8.5 TRW stock style pistons, and the 70cc head volume, I'm getting decent compression with this Lunati cam. (284adv. [email protected]/.458 lift single pattern)

After all the research and the help here, I should be at 8.4 to 8.5 compression. If that doesn't fit the formulas, it's possible that the decks were not stock before the .015" clean up even though the machine shop said they were???

As Rusty had stated earlier, maybe with this compression, (even though I'll have the timing cover off some time soon), there's not much reason to change the cam right now??? (unless I change everything, including pistons.)
I know there are differing opinions but all are appreciated, and I'm learning some stuff!