Hmmm nice one Jon,
What make is it? BSA, Enfield, LSA? if it's not marked in the butt socket RHS then check the right hand bolt guide at rear of action for either SSA or NRF but I think 1918 is too late for them.
As for Kick well the worse 303 for felt kick to me was the P-14 but change the stock to a sportign oen and it was drastically reduced
.
None on the No1 Mk111's had steel butt plates they were brass soem of the No4's had an alloy plate but most of thsoe were brass too. The P-14 was steel I seem to recall.
Oh and the std weight of a military trim No1 Mk111 is about 9lbs.