Timbalai 1948 RSO Borneo (Sears Chains) - EPSG:29871

WKT

PROJCS["Timbalai_1948_RSO_Borneo_Chains", 
	GEOGCS["GCS_Timbalai_1948", 
		DATUM["D_Timbalai_1948", 
			SPHEROID["Everest_Definition_1967", 6377298.556, 300.8017]], 
		PRIMEM["Greenwich", 0.0], 
		UNIT["Degree", 0.0174532925199433]], 
	PROJECTION["Rectified_Skew_Orthomorphic_Natural_Origin"], 
	PARAMETER["False_Easting", 0.0], 
	PARAMETER["False_Northing", 0.0], 
	PARAMETER["Scale_Factor", 0.99984], 
	PARAMETER["Azimuth", 53.31582047908623], 
	PARAMETER["Longitude_Of_Center", 115.0], 
	PARAMETER["Latitude_Of_Center", 4.0], 
	PARAMETER["XY_Plane_Rotation", 53.13010235415598], 
	UNIT["Chain_Sears", 20.11676512155263]]

WKT2

PROJCRS["Timbalai_1948_RSO_Borneo_Chains", 
	BASEGEOGCRS["GCS_Timbalai_1948", 
		DATUM["D_Timbalai_1948", 
			ELLIPSOID["Everest_Definition_1967", 6377298.556, 300.8017]], 
		PRIMEM["Greenwich", 0.0], 
		CS[ellipsoidal, 2], 
		AXIS["Latitude (lat)", north, 
			ORDER[1]], 
		AXIS["Longitude (lon)", east, 
			ORDER[2]], 
		ANGLEUNIT["Degree", 0.0174532925199433]], 
	CONVERSION["Rectified_Skew_Orthomorphic_Natural_Origin", 
		METHOD["Rectified_Skew_Orthomorphic_Natural_Origin"], 
		PARAMETER["False_Easting", 0.0, 
			LENGTHUNIT["Chain_Sears", 20.11676512155263]], 
		PARAMETER["False_Northing", 0.0, 
			LENGTHUNIT["Chain_Sears", 20.11676512155263]], 
		PARAMETER["Scale_Factor", 0.99984], 
		PARAMETER["Azimuth", 53.31582047908623], 
		PARAMETER["Longitude_Of_Center", 115.0], 
		PARAMETER["Latitude_Of_Center", 4.0], 
		PARAMETER["XY_Plane_Rotation", 53.13010235415598]], 
	CS[Cartesian, 2], 
	AXIS["Easting (X)", east, 
		ORDER[1]], 
	AXIS["Northing (Y)", north, 
		ORDER[2]], 
	LENGTHUNIT["Chain_Sears", 20.11676512155263], 
	ID["EPSG", "29871"]]

Data from @esri/proj-codes

{
  "wkid": 29871,
  "latestWkid": 29871,
  "gcsWkid": 4298,
  "macro": "PE_PCS_TIMBALAI_1948_RSO_BORNEO_CH",
  "name": "Timbalai_1948_RSO_Borneo_Chains",
  "wkt": "PROJCS[\"Timbalai_1948_RSO_Borneo_Chains\",GEOGCS[\"GCS_Timbalai_1948\",DATUM[\"D_Timbalai_1948\",SPHEROID[\"Everest_Definition_1967\",6377298.556,300.8017]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Rectified_Skew_Orthomorphic_Natural_Origin\"],PARAMETER[\"False_Easting\",0.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Scale_Factor\",0.99984],PARAMETER[\"Azimuth\",53.31582047908623],PARAMETER[\"Longitude_Of_Center\",115.0],PARAMETER[\"Latitude_Of_Center\",4.0],PARAMETER[\"XY_Plane_Rotation\",53.13010235415598],UNIT[\"Chain_Sears\",20.11676512155263]]",
  "wkt2": "PROJCRS[\"Timbalai_1948_RSO_Borneo_Chains\",BASEGEOGCRS[\"GCS_Timbalai_1948\",DATUM[\"D_Timbalai_1948\",ELLIPSOID[\"Everest_Definition_1967\",6377298.556,300.8017]],PRIMEM[\"Greenwich\",0.0],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],CONVERSION[\"Rectified_Skew_Orthomorphic_Natural_Origin\",METHOD[\"Rectified_Skew_Orthomorphic_Natural_Origin\"],PARAMETER[\"False_Easting\",0.0,LENGTHUNIT[\"Chain_Sears\",20.11676512155263]],PARAMETER[\"False_Northing\",0.0,LENGTHUNIT[\"Chain_Sears\",20.11676512155263]],PARAMETER[\"Scale_Factor\",0.99984],PARAMETER[\"Azimuth\",53.31582047908623],PARAMETER[\"Longitude_Of_Center\",115.0],PARAMETER[\"Latitude_Of_Center\",4.0],PARAMETER[\"XY_Plane_Rotation\",53.13010235415598]],CS[Cartesian,2],AXIS[\"Easting (X)\",east,ORDER[1]],AXIS[\"Northing (Y)\",north,ORDER[2]],LENGTHUNIT[\"Chain_Sears\",20.11676512155263],ID[\"EPSG\",\"29871\"]]",
  "description": "Timbalai 1948 RSO Borneo (Sears Chains)",
  "authority": "EPSG",
  "version": "4.4(9.0.0)",
  "deprecated": "no",
  "areaname": "Asia - Brunei and East Malaysia",
  "extent": {
    "slat": 0.85,
    "nlat": 7.67,
    "llon": 109.31,
    "rlon": 119.61
  }
}