Model 99-bis chainring _ 40 teeth
I usually don't like anodized chainrings. But this one (probably from the very early 1980s) is a bit more clear over a polished finish compared to even later examples which had a far more flat satin finish. I found this in new-old-stock condition at a local bike shop and grabbed it for a very reasonable low price.
I may use it as is on my new (earlier) model 99 crank. If it does not look quite right with an earlier style polished outer ring I could easily modify it for a more suitable look. This is good size chainring for either a middle ring on a Triple crankset or as an inner ring if configured for a Double chainring crankset.
The outer circle of holes are set at 122mm. and bored at a standard 10mm diameter. I think that was a cost saving decision. It would allow the very same chainring blanks to be easily re-stamped to fit a model 105 or 104 crankset.