The only way I see that happening is using recipes to give that to you, then discarding whatever you started with. I made a primitive no iron character and immediately discarded the iron axe and knife and made stone versions, for example.
You can make a test menu (I have a diy_test.txt file for my test recipes) and then assign it a letter in the menudef file when I want to use it (I'm using Q). You can just make recipes with no ingredients and 1 minute duration to get those items and off you go.
Pretty much that. Ps, its a little off topic for the BAC mod thread. Please start a fresh thread for more discussion on that. I will add just a quick bit more.
Shift-D when you stand on things discards them
You will need the menudef like Signatus described. The menudef_BAC.txt includes mentioning a few letters free and as of right now IIRC you can use two of the letters for your own menus.
Once items are made in the game you can remove the menu entry. The data is already in the character save. If you had custom grahpics you will want to leave those in the graphics directories as the pointer will come up with an invisible blank if no match is found (which is better than crashing the game)
For your free items you will need to match the vanilla name exactly in a recipe like
[SUBMENU_START Freebie]
.Exact name. /1m/
{Rock} '+free start'
[SUBMENU_END Freebie]
Aside from that I started Novrus with the "abandoned camp" to reprsent random gifts from his family, and boy it weren't much. You could also reimagine the disasterous hunt as gifts given rather than your father's horrible death.