Phillips brand c1950? Please help me identify this awesome old frame! Here is all I know:

Seems to be a 26" frame. 

Lug construction on main frame but the seat stays are bolted on.

Serial number at seat clamp: 3051CT

Has strange hole in bottom bracket shell.

"Made In England" stamped on underside of BB.

Forks are of a pretty old construction style.

Has tiny holes to mount a badge on the head tube.

Possibly a Raleigh Bomber from the early 80s, but I am thinking it is a 1940s-1950s Phillips frame from their 'Cyclemaster' line. That filler hole and no Raleigh stampings make me think it is a Phillips...

Attaching pics of my frame, plus two from the Phillips catalogues. Bottom right is frame, fork is center in the other pic.

What do you all think? Year range is hard to figure out from Google.

(Raleigh bought Phillips in the 60s i think, and looks like they dug into Phillips' back catalog 1980 for the Bomber frame - it's nearly identical.)

THANKS!
There are numerous Vintage Bike Resource sites available. Old Roads.com, The Headbadge, are a couple I use. The Headbadge has a nearly complete list of Raleigh Catalogs for most years. It appears you have a frame at least similar to a Canadian Model 99 Gents circa 1954. It can be difficult to date a Raleigh bike visually as many models were made for decades with very few visual changes. The bolt-on chain stays aren't that unusual. I haven't found any definitive reason why they were used. Some feel it was just a hold over from the days of fully enclosed chain cases. It may also may have been to allow the chain to be removed without breaking the chain. For many owners a Raleigh was a once in a lifetime purchase. Hence the oiler port on the bottom bracket and wheel hubs.