1918 SMLE .22 Parher Hale

Gent's; I've been having a closer look at my Standard Small Arms made peddeled scheme 1918 SMLE.
There are a couple of odd details; that i would like to find out more about it if possible.
The rifle has been converted to .22 by Parker Hale; It appears to be a solid .22 barrel and not a re-tube. The barrel appears to have a 1918 date code on it and military ownership marks and British Proof for .22.
However the wrist is not marked with the ususal No2MkIV* or .22 markings.
It still wears the original woodwork and steel butt plate by Linley and Co. It is matching numbers.
is it possible that it was built as a .22 directly in 1918 ? or is it more likely that it was built as a .303 then converted later in the year.
Here are some photos. Does anyone else have a similar model without the .22 wrist marking?
Attachment 109505Attachment 109506Attachment 109507Attachment 109508Attachment 109509Attachment 109511Attachment 109510

PH converted it for some commercial customer, who didn't require them to change the markings. The PH name change occurred in the 1930s.

It would be nice to see a close up picture of the muzzle and crowning.

I'll check and see if I have a photo of the muzzle; if not I'll take one at the weekend. It's not marked "Parker rifled" that's for sure.
Thanks for your input.
If it is a tubed barrel; would we not see the original .303 stamps struck out?

here is a photo of the muzzle as requested. After looking closely at the muzzle; I thinl it may actually be a tubed barrel. A very small circular line on the muzzle is visible. Maybe some of our expert member's could confirm. Thanks.
Attachment 109639