Ah, that's more better. I was thinking that those sleeves took the place of the /7 adapter buttons, which fit into the indexing cutouts in the bottom of the /7 rocker blocks, providing good alignment. It might be nice to make "indexing sleeves" for the early /6 heads, but it's not that big of a deal to squeeze the /5/6 rocker blocks and set the axial play when torquing the heads. Simpla Fi and all that.
Here is the plan: I'll go ahead and use the existing rockers to get this project running. Look for a set of the /7 rockers on fleabay and IBMWR etc and replace the rockers by 1000Km or 600Mi, when I'd retorque the heads anyway. Or at least ASAP.
'73 R60/5 Toaster