I did receive the photos you sent in this morning that were forwarded to me via our website moderator. The abrasions themselves can likely be managed at home with a sterile cleaning using Betadine diluted 50:50 with warm water and then flushing the area daily thereafter with sterile saline from your local pharmacy. However, if you are also seeing swelling, this could pose a problem.
Swelling underneath the skin following trauma is typically either of 2 things: an Abscess (infection underneath the skin) or a Seroma (blood filled sac) . An abscess will need to be treated by your vet, by having the area drained and then he will need to be placed on a short course of antibiotics. If this is a Seroma however, it will likely heal on its own as the body slowly reabsorbs the blood. As long as the Seroma does not get any bigger, which would indicate that there is continued bleeding underneath the skin that needs to be ligated via surgery.
There really isn't a good way of knowing if this is Seroma or abscess by looking on the outside; however, with abscesses they are typically painful and will eventually lead to fever and illness (lack of appetite, vomiting) in most cases. Seroma's can be mildly painful, but won't cause a fever. So since you are limited on funds you can roll the dice and see if this thing causes systemic illness or not, or you can try to apply for financial assistance to get Wilber looked at immediately to make sure there isn't an abscess present.
Here are some links for financial assistance. I
https://carecredit.com/vetmedHere a couple of still up and running grant options:
carecredit.com
redrover.org/relief/urgent-care-grants/ (typical grant amount is $200)
all-creatures.org/gcm/help-cf.html - $50 maximum aid WHEN they have funds.
a couple of 'special situation' ones:
fveap.org - Vaccine Associated Sarcoma only
thepetfund.com/ - Non-basic, non-urgent care (cancer treatment, heart disease, etc.) ONLY.
! hope that this was helpful and hope that your pet Wilber is able to make a full and speedy recovery from his traumatic injury. Take care!