When I have finished a restoration and I have a perfect BLO finish on the woodwork, the best way I have found to add handling marks and to make it look used, is to handle it and use it often.
Every rifle that I own is milsurp except two, I would not hesitiate to sling any one of them on my shoulder and take out to the bush. I TRY the best I can to be careful, but if they do get dinged up, oh well, that will be for the next generation of collectors to address.
In a similar way, all the webbing and kit that I use started out unissed and squeeky clean. Every stain, tear, fray and boo boo has been put there by me

It adds character. Nothing wrong with honest wear to my eyes.
The worst form of abuse to a rifle is not to clean it after shooting. That will ruin the bore in short time, especially if corrosive ammo is used. All that is needed is to keep them clean and the bores oiled. Just enjoy the things and don't worry about it.
Unless you have a mint specimin with perfect flawless finish, a few more dings won't hurt the value of a used battle rifle too much. Anyway most times, dents in the wood can be steamed, raised and removed if a real concern. Me, I'd just cuss, rub the dent, then live with it.
I used to play with all my Dinky cars too.
