Missing Part/Seal to create toilet rim holes

We moved into a new(er) home over Thanksgiving and over the weekend I finally made it into the half bath in our basement to do some much needed first-time cleaning. I immediately noticed how dirty the front of the bowl was. While cleaning I realized that during the flush, water was not coming out of the rim at the front of the toilet bowl. I figured the rim holes were clogged and went upstairs to get a mirror and coat hanger. Needless to say when I stuck my mirror down there, I was quite surprised to see that there were no rim holes. It appears there is some kind of plastic lip/seal that is broken out of 95% of the rim and so when the water comes into the top of the bowl it just gushes down the back portion of the bowl. There is a little piece of the "plastic rim sealer" (for lack of a better term) that is not missing and it basically looks like a half moon-shaped piece of plastic with rim holes at the apex of the curve. The toilet is made by Crane Plumbing but I have not found anything on their website or anything on the net to even identify what this part would be called. Any help or suggestions would be greatly appreciated.

Thanks,

Mark in KC

I took a closer look at the plastic piece that remains up under the lip of the bowl and it appears that maybe it is not broken. There are no holes in it - rather it simply directs some of the water entering from the back of the bowl to go around the side of the bowl to create a whirlpool (albeit a very weak one) effect. I'm now wondering if there is no broken piece but instead the toilet was designed this way. Surely not? It's made by Crane but I can't find the model number on it anywhere. The house was built in 1996-1997 so the toilet is probably about 7 years old. Thoughts? Anyone ever hear of a toilet designed like this?