That is an interesting rifle. I have an en-bloc clip Steyr retailed by Dicksons with a serial number very close to this one. I think it's possible a batch of Steyrs and Mannlichers was made up by an outwork firm very soon after 1900, and they sold them throughout the trade, Dicksons buying some of them.
Another member here has an H&H identical to my rifle, and they both have butt stocks that look like this one.
I do not know if Dicksons had a separate ledger for bought in guns, mine is not in the daybooks either.
I would like to see a picture of the frontsight for comparison.