Joined: Jan 2010
Posts: 9,835
Likes: 1,816
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
The 13T cog for a 7s Suntour freewheel can be hard to find in good condition.
I've come across a couple of such freewheels having a cracked (split) 13T cog, and never found parts to repair them.
Too many of the 7s Suntour freewheels seem to start with a 14t cog, and no Shimano cog will match Suntour's threading unfortunately.
I think that your freewheel will work fine with just one broken tooth, but may wear out sooner if it ever wears out at all.