I have been having similar dilemma trying to ID various Parker Hale mausers. The "commercial" ones have a solid left side rail on the action - the M98 ones were made from military (I think) - they have that thumb cut into that left rail. At various times, Parker Hale sold both versions. When you dismantle that rifle, odds are good there will be the word "SPAIN" stamped along the side of the rear tang - and sometimes is ground or scratched away - sometimes still readable - I had read that PH was using receivers made at Santa Barbara arsenal for many years - Husqvarna and others were using nearly identical commercial receivers made by FN in Belgium.
Is also a thing about "C" profile or "H" profile inside that front receiver ring - whether left side bolt lug broach cut taken all the way through or not. I am pretty certain both styles were used by Parker Hale, but do not know how that relates to maker of which receiver...
Look along the barrel channel and inletting - might find the word "SILE" stamped into the wood - was a stock making company in Italy that supplied a lot of the wood stocks on many PH rifles.
Since made in England, it will have Birmingham stamps on the chamber - sometimes underneath the wood line - at or near bottom of the chamber on the barrel - that mark often small - like 1/8" tall - I use magnify glass - will be crossed swords - letter to left, a "B" to right, then Inspector number or letter below - can go on Internet - Hallowellco.com (?) and find table to get the date that stamping was done - based on the letters and numbers.
I had asked some time ago if there was a reference book to ID the various PH mauser based models - consensus of the CGN responders at that time was basically to start collecting old Parker Hale catalogues and see what was offered each year - multiple that looked similar, but maybe only the stock was different?? Had 1000, 1100, 1200, then 1000C, 1100C, 1200C, then Safari, then Safari Super, some had model name scrolled onto left side, some had nothing there. Some made for screw attached scope bases - some had the PH scope bases soldered or brazed on at factory - no screws used. And so on.
As per other recent CGN threads, many PH Mauser will not permit single feed - as were the original military Mausers, must be fed from magazine. I have a couple that way - can not drop a cartridge into chamber and close bolt without other manipulation. I also have some that the extractor claw face has been ground to permit single feeding - I do not know if that was done at Parker Hale or if done after market. As mentioned, some have detachable magazine (NOTE - three screws hold those actions to bottom metal - have to remove the release lever at front of trigger guard loop - look up inside for that third screw), and some have hinged floor plates. Multiple chamberings over the years, but not always every chambering, every year - so there is 243 Win on up to 308 Norma Mag here - I am sure there were bigger and smaller, but I do not own any.
At least two versions of adjustable trigger came with the Parker Hale rifles / Santa Barbara actions - should be able to find adjustment instructions for both on Internet - just make sure you have the correct one for the instructions that you found,
