Thorp T18 Plans question

I'm helping an aero engineer friend research details of successful
homebuilt aircraft undercarriages. (for some calcs for a book)

I borrowed my mate's T18 Plans, from which he built a honey of a T18.
my mate used a prebuilt and tempered Brock undercarriage so didnt need
or buy the undercarriage drawings. the very drawing I need is missing
and since he bought a fully assembled component he has no real idea
what the materials were that were used in the gear. btw the Brock gear
has done over a thousand hours so far without a single problem so
Ken's work endures as a memorial to his talent.

I have a partial copy of drawing 516 which gave the bolt sizes used to
attach the gear.

Drawing 515 has the details I need.
if you look at the gear leg it starts at the top attach point, runs
down through a sleeve for about the centre 3/5th of the leg, to which
the centre attach point is welded, then down beyond the sleeve it
terminates in a plate to which a cessna style bolt on axle gets
fitted. (the axle and brakes are actually a cleveland set)

is the centre component of the gear leg a tube or a rod? my builder
friend couldnt say. what are it's dimensions, wall thickness etc.
what are the dimensions of the sleeve, wall thickness etc?
what are the dimensions of the crosstube tube?
what is the thickness of the wraparound plate that the neoprene
components and washers are bolted through?
I'm assuming it was all made from 4130, is that correct?

I know it was heat treated to 180,000 psi ultimate.

appreciate a help from anyone with a full plans set.
Stealth Pilot
Australia.