Hi, the loco looks good, obviously it has not had much use.

Short answer is that the light build is not a fuse.

Are there and humming sounds from the loco when you try to operate it?

If you are good with a multi meter try checking you are getting power to the decoder by putting one probe to the red wire and the other to the chassis.

Also check the carbon brushes on the loco have not become covered in oil from when you lubricted the loco.
There should be instructions in the set that tell you when and how much to lubricate. Over oiling has caused people trouble in the past.

You can easily check the bulb by removing it from the loco and applying a little power to it directly from the transformer.

Also check that all the little white dip switches are in the off position if you are running it analogue with the transformer and no digital controller. If one of those has been accidentally bumped on during work, then the loco may not respond in analogue.

Cheers....

Mike