PART NO.  SPL.PAGE  DESCRIPTION                                                             
1A2032    15.A.3    Plate -camshaft locating -[Fin.(E)GB258 -1G1361 alt.no.]
1G1361    15.A.3    Plate -camshaft locating -[Fin.(E)GB258 -1A20321 alt.no.]
11G99     15.A.3    Joint -camshaft locating plate [Fin (E) GB258]
11G136    sup.3     Plate -camshaft locating -(engine unit, sup)
11G136    16.A.3    Plate -camshaft locating -(engine unit, 1600)
11G136    16.A.24   Plate -camshaft locating -(engine unit, 1622)
HNS0406   15.A.3    Screw -locating cam plate to crankcase
HNS0406   sup.3     Screw -plate to crankcase (3) -(cam locking, engine unit, sup)
HNS0406   16.A.3    Screw -locating plate to crankcase (3) -(camshaft, engine unit, 1600)
HNS0406   16.A.24   Screw -locating plate to crankcase (3) -(camshaft, engine unit, 1622)
HNS0406   TC.A.6    Screw -plate to crankcase (3) -(half speed shaft, engine, Twin Cam)
LWN604    15.A.3    Washer (shakeproof) (camshaft locating plate, engine unit, 1500

Before addition of the timing chain tensioner, the very early production camshaft locating plate 1A2032 and alternate part 1G1361 would have been trilaterally symmetrical without the bump on one side. The mated11G99 joint (gasket not illustrated) would be the same shape. The later plate 11G136 with the bump is shown in the pictures below left. Original cam locating plate would have been bi-metal, steel plate with white metal bearing material rear surface. Modern replacement parts may be bi-metal steel with bronze bearing material rear surface (as shown in the pictures). Either material is functionally acceptable.

Note that the first 159 1500 engines did not have a timing chain tensioner. When the tensioner was added at (E) GB259, there were passages added in the block, just behind the front plate, to pass oil from the front cam bearing to the chain tensioner. The engine front plate was modified, the camshaft retaining plate (item 18 in the illustration) was modified (different shape and part number), and the joint washer (gasket) was deleted. The first cam retaining plate 11A2032 had an alternate part number 1G1361. After the change, the cam retaining plate would be part number 11G136.