You have to check to see what the seller has.
There are three major versions of the SMLE Mk I** IP; one's converted from SMLE Mk I rifles, one's converted from early SMLE Mk III's and one's converted from MLM/MLE's. RCS's beautiful examples are on the first and most common and numerous type.
From what you initially described you have an ultra rare Ishapore SMLE Mk I* IP that was upgrated later to a SMLE Mk I***. Ishapore only made 3,020 betweem 1907-09. An example of a Ishapore SMLE Mk I regardless of condition is an excellent find for a collector. Grab it if you can and post pic's!!
Attached are photo's of mine, the only one I have seen. No RFI conversion marks on the right reciever as seen