I have a Ford 1100 and several attachments to go with it. I was looking for something with a little more hp, and came across a JD 2555. The first thing I realized, was that hp is rough on attachments. Things I used to do with the Ford, when done with the same attachment behind the JD, simply destroyed the attachment. Most of them I have been able to repair, but it just happens again, in another place. I can use some of them carefully, but basically I need something heavier than what I had with the Ford. Some of the attachments have been beefed up to withstand almost 5 times the hp, but basically, I am in the process of changing out my attachment line, with items that can handle the hp.
Since the cost of improving this is expensive to say the least, I will probaby sell the little Ford, along with all the attachments that are left (not destroyed) and use the money to purchase heavier attachments.
This is coming from a guy with capabilities of reinforcing, and strenghtening almost any attachment, within reason. I just can't make silk out of a sow's ear.
Basically, you can reinforce the box blade, by carefully bracing and reinforcing it in everyway, and if you are careful, it will last you a lifetime. Your skills at welding and fabrication will come into play with this. If you have to pay someone to repair it, and reinforce it, you might be better off saving the money to purchase a heavier grade of boxblade.
All of this is based on my experience, not on knowledge of your particular equipment. I am not familiar with the Hawkline BB, just figured you might apply my experiences to your situation.
David from jax