MKI is too much a contraption, though a lovely bit of engineering.

Webley MKIII certainly an elegant hansom rifle. Just didn't shoot well enough with the pellets of the day and that tap loading breech.

Webley Vulcan: MKI, MKII, think even MKIII?? MKI great boys rifle but that trigger is hard. MKII getting better. MII Walnut Deluxe was a great looking rifle too. But with all of them the trigger couldn't get them to shoot beyond the farmyard.

Webley Omega was the best yet. A great handling sporting rifle, one of the best stock designs ever done. A better trigger than the Vulcan, but still not good enough compared to the competition. Wish they had done them in walnut.
The Eclipse was a great effort which could have come off if it hadn't the same trigger as the Omega. It could but wasn't a BSA Superstar or HW77.

Longbows, finished off the the action and trigger to what is necessary, but then changed the stock. Good shooting rifle but not as elegant as the MKII or Omega.

So to me Webley never made a "best" as all had at least a major fault if not two. I have an Omega and MKI, both in .22, which about says it all from me.