UNKNOWN 505 GIBBS MAUSER - Anyone recognize these names?

Hello All,

I recently acquired this wonderful 505 Gibbs. I was told it had South African Heritage, but I'm not sure. It appears to me to be a Brevex Action, due primarily to the markings on the action's bottom; "M 400" but again, I'm not sure. Perhaps the "VB" monogram will be recognized by someone.

Based on the patina of the recoil pad and the stock, I think this rifle was originally built in the 1950's, and had a "face-lift" to its current configuration in the 1970's. (There is evidence that the action once had a side mount.)

Here is all the scoop in hopes that someone might know the maker, or the markings. Ask additional questions as required ...... thanks

The rifle is a 505 Gibbs caliber, Square Bridge Magnum Mauser that has hand engraved on the center top of the barrel:

"Customized by C. S. Labuschagne"

On the top of the barrel very near the muzzle it is hand engraved:

"Bundock"

On the bottom edge of the engraved floor-plate, nearest the trigger guard, it is hand engraved:

"A. D. Winkler" (he is the engraver)

On the brass escutcheon that is inlaid into the bottom of the stock, it is hand engraved:

"CSL" (I'm assuming its C. S. Labuschagne's initials)

On the bottom of the trigger guard it is hand engraved:

"1014"

On the left side of the receiver it is hand engraved:

"1014 / 505 Gibbs"

The left side of the barrel has the number "1014" stamped.

The bottom of the action is stamped"

"M400" "4.2" "VB" (monogram)

I can find no other markings on this rifle.

Other specifications are:

Barrel Length - 21"
Weight - 9lbs 12 oz
LOP - 14-1/8"

Quarter Rib w/ single standing rear site
Rib is cut for Warren Rings (Scout-rifle position for scope)
Folding hood front site
Grip Cap Trap

Here are the pictures