Created grid system on Betio map and plotted two coordinates from Battalion reports below. Can see the crater where the guys went in with the amtrac so that possibly confirms the details for one location. Don't have a sharp enough eye on the R1/R2 boundary but recall there was an AB gun there.Six digits didn't make sense but when scaled down, it seemed to work as the Combat Team 2 CP mapped well at KH 235123 in another effort.
From LT 2/2 Operation Summary by Major Howard Rice, 27 November 1943
The first platoon of “E” Company landed independently on the left half of Beach Red 1 after becoming separated from the remainder of the Company at H-Hour. The platoon went into position in a large bomb crater at approximately KH - 169120. In this position the platoon destroyed an enemy strongpoint and silenced numerous enemy snipers. The platoon leader was killed at this point. The platoon was greatly weakened by heavy casualties sustained in reaching this location.
HQ LT 3/2 Unit Journal Tarawa Operation November 20
D-Day
1030 Msg to CO LT3-2 from “K” Co. “The anti-boat gun is located at KH 195123.