Hit up a mod in the #avatarhelp channel in my discord server!
Chances are, we already have the answer for you!
Generally speaking, no. However- If its like a be all end all, "I only have a quest headset and no one to upload for me" then... maybe!
But no lol, uploads are a no go.
I feel you, but no. All model sales are final sale.
Join the discord! The mods and I are happy to help- don't stress!