The first letters on the plate identify the type/series of plough, e.g. PU. BE. BH. C.
CM. CW. CMR. CWR. DM  (additionally for the C type, "W" = wide and "R"
= reversible).

The next set will tell you how the plough is made up and with what type
of components

2. 3. 4.    Number of furrows.
M.          Medium frame.
1.           Rigid beam.

2.           Trip beam.

3.           Category 1
linkage.
4.           Cat 2 "
5.           Steel land
wheel.
6.           Rubber-tyred
wheel.
9.           Plain disc
coulter, non-tilting.
10.         Plain disc coulter,
tilting.
11.         Cut-away (scalloped)
disc, non-tilting.
12.         Cut-away disc, tilting.

19.         Knife coulter.
17.        Skimmers for non-tilting
coulter.
18.        For tilting coulter.
20.        Standing skimmer (heavy duty).

21.        Standing skimmer.

Plough bodies.
11.        General purpose.
12.        Semi-digger.
13.        Deep-digger.
14.       Universal.
15.       Ley.
16.       Continental.
18.       Semi-digger Dandy bar point.
19.       Uruguayan.

Shares.
S.       Steel.
C.      Cast iron.
G.      Spheroidal Graphite.

Serial Number

The actual serial numbers is the last set of numbers on the plate and
denotes the build number of the plough. All serial numbers start with 10,
(one zero) the numbers after this will give you the actual build number. .