/ic/ - Artwork/Critique

This is the reference: https://previews.123rf.com/images/gualberto107/gualberto1070805/gualberto107080500169/3087003-double-barrel-shotgun.jpg

I feel like i nailed the reflections from lighting but maybe not the shading. Also, this started out as an attempt to copy it as well as i could but along the way i just noticed i had to start over to nail it picture perfectly so i just kept doing my own thing, should i start over in the future?

Also, im not quite sure its a good idea to keep the lines when youre doing lighter and darker areas because these two styles maybe dont mix well? Should i use lines as a first draft and then change it into lighter and darker shades to mark different shapes and objects?