Wow! Neat! I would like to see pictures. I'll tell you what I can from the information you have provided thus far. More information and some images, may help narrow down the period.
The 3 digit model number, 211, suggests that the pipe was made for the US market. These 3 digit codes are also known as Nichols numbers, named for Barling's US distributor. Around 1926-7, Barling reentered the US market and set up a separate numbering system for their US market product.
The "EL" indicates the chamber size. EL was "extra large" and only entered Barling's product line in the late 1930's.
The lack of a COM stamp, Country Of Manufacture, next to the EL stamp suggests that the pipe is early, because Barling was very frugal with stampings prior to WW2. Unfortunately, they were also very inconsistent with stampings, so the lack of the COM stamp isn't a lock.
The inner case logo is typical for a Barling case of the period. The term "Special" when applied to the case, refers to this being a cased pipe and is not a grade. Barling had a "Special" grade, but that was always stamped on the shank of the pipe.
Ye Olde Wood is a grade, a step up from their standard "Barling's Make". Barling collectors refer to this grade as YOW.
So your pipe dates to somewhere between the late 1930's and 1950's, when your grandfather passed.
Look at the underside of the stem, near where it meets the shank, and see if you see either the letters Reg'd with a line of numbers below it, or the words "Barling Design". Not all stems had this stamping, but a great many do and it also helps set the time frame. If you see the Reg'd stamp with the numbers, that's a patent stamp and pipe was made no later than 1950. If it says "Barling Design" then the pipe is no earlier than 1950.
Hope this helps.