I believe some 066 saws were sold without a compression release valve. The cyllinder is the same - just a plug in place of the compression release valve. The cover would also be the same only with a rubber cover over the hole.
I would also think that you can retrofit the saw with a compression release valve. Simply remove the plug and put in the release valve.
The elastistart cord is something that also can be added.
Parts at your dealer.
Hal