Trailing arm- date of manufacture

[Peter Macholdt <vze2846b@verizon.net>]

I have just finished cleaning up the trailing arms on the 250 and thought
I'd check to see if they were the proper arms for my car. In his book, Roger
Williams states "...Triumph's casting sub-contractor was meticulous in
incorporating the date of casting on the outside of each trailing arm...".

Maybe not that meticulous, I can't find this date on my arms. Anybody have a
clue where on the arms this info might be? The only info I found on the arms
is:

Stanpart
308225
V3109
DD1

Peter
'68 TR250