Hi again Tony,
So your silver Briggs is a model 60102, and was manufactured on the 19th January 1968, which makes it an early engine. wink
The sprockets and chains look in great condition...I also notice the the front roller end-caps have been replaced with the later plastic ones, the original ones were alloy and you can see the holes in the roller where the rivets were drilled out that were used to attach the alloy caps.
cheers2

Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin