There was a rifle and magazine combo for sale here a while ago. The seller was after "the best offer over $4,000". I called him and managed to work out the rifle was a Patt14No1 but it had no military markings on the receiver. He said it was a civilian model Parkers had kept making after the war for "miniature rifle" club shooters The woodwork was near immaculate, but had been finished with a gloss laquer. The magazine was in good condition, but it hadn't come with the rifle- he said he'd put them together for the sale. I figured a bid of $1800 was maybe a little above market value, but offered it anyway. Sorry to say the seller got abusive. Last I saw, before it expired on the sale site it had been reduced to $2200.

When they were made, the Parker Hiscock magazines (Magazine .22 Inch rifle, MkI) were for fitment to the .22Short Rifle MkIII and the Patter14 rifles (LoC 17621 dated 21 Dec 1915) The Pattern 14 No1 was joined in April 1916 by the Pattern 14 No2.
The magazines were declared obsolete by LoC 23766 on 8 Nov 1920 and ordered returned to store for disposal. Up to this time, there had only been one other .22 Short Rifle introduced, being the .22 RF Short Rifle Pattern 1918. This model utilized a "conveyor cartridge" through the standard .303 magazine, so couldn't use the Parker Hiscock magazine. The .22 Short Rifle MkIV (which became the Rifle No2 MkIV in 1926) was not approved until 19 Nov 1921, almost exactly a year after the PH magazines were recalled.
Bottom line, if you see a Parker Hiscock magazine in anything other than a .22 Short Rifle mkIII (converted from ConDII and II* rifles) or Pattern 14 No1 and No2 rifles, it does not belong there.

Perhaps the new owner of the sale rifle posted above will turn up here, would be good to know a ball-park figure.