No 4 Forestock conversion

I'm building up a rifle from parts and bought a Mk 2 forestock from an online vendor.
The wood arrives today and its brand new in wrapper. Green inside/beige exterior.(pics)
I know I have to patch a piece to the rear of the timber area so I want to check it out.

Anyway, I try to fit my no 4 body into the in-letting and theirs a wooden protrusion near the front right receiver reinforce that will not allow the body to drop in.

Question, is there a reason the additional wood is located in that particular area?
If someone could give a heads up why the additional material is there before I unnecessarily remove the offending piece that would be a great help.
I don't want to remove or destroy anything that's there for a specific purpose.
I can find another piece of wood if necessary, this ones pretty decent enough to leave alone if the need be.

Thanks for any replies-Brian

I can not really identify what your on-line vendor may have sold you - an FYI - from Charles Stratton book "Lee-Enfield No. 4 and No. 5 Rifles" - he identifies nine different configurations of No. 4 bodies that were used at one time or other - a chart on p. 37 shows which variation of body was used by which of 7 different makers at different times. For example, Fazackerley used 6 different variations of receiver bodies at various times; Maltby only ever used one variation. No telling that the stock that you have was actually made for the receiver that you have? Obviously different layout. That particular "lump" on right front of your receiver seems to have been a carry over from earlier SMLE magazine cut-off hinge - was not present on what Stratton calls 3rd and 7th variations of No. 4 receiver bodies. But nothing that I see to explain that circular portion that is removed, unless that was part way through a process of milling out and then stopped for some reason??