Mainsheet mid-boom rigging

Just picked up a DS1.
Everything appears complete except for the mainsheet block on the mid-boom.
There is a short section of t-track that the block should attach to.
Does anyone know a source or spec for the block that will attach to this t-track. The track is about 20mm wide. Unfortunately there doesn't seem to be a standard that the different manufactures adhere to.
I have been searching other posts and pictures on-line. I see other boats with the track, but can't find anything with enough details.
I guess the other option is to add boom bailer: https://www.drmarine.com/proddetail.asp?prod=DR312
Here is a picture of what my boom looks like:
Here is a picture that GreenLake has posted:

Here is a picture I found on-line to show the location that I am talking about:
Everything appears complete except for the mainsheet block on the mid-boom.
There is a short section of t-track that the block should attach to.
Does anyone know a source or spec for the block that will attach to this t-track. The track is about 20mm wide. Unfortunately there doesn't seem to be a standard that the different manufactures adhere to.
I have been searching other posts and pictures on-line. I see other boats with the track, but can't find anything with enough details.
I guess the other option is to add boom bailer: https://www.drmarine.com/proddetail.asp?prod=DR312
Here is a picture of what my boom looks like:
Here is a picture that GreenLake has posted:
Here is a picture I found on-line to show the location that I am talking about: