Hello, everyone.
I'm on a journey to identify this frame.

The previous owner said this was a copy of some Look design, but made by Leader in aluminum and with Raleigh decals.
It got my attention because the welds are clean.
I reached Leader and they said that never made this type of frame.
I figured that it looks a lot like a Look KG131. Although, I reached them and the answer was the rear brake cable passage in KG121 and KG131 was internal in the horizontal tube with the sheath and not external like mine.
I found a serial number in the left hook its says L501249.

Could anyone help me identify the manufacturer?
Thanks a lot. Here are some pics: