First and foremost, very sorry to hear about your brother...I'm just glad to hear that he will make a full recovery. Unfortunately in this business, things like this happen time to time and nobody can ever predict it. Second, the insurance should cover ANYTHING that was damaged in the accident...you shouldn't even need receipts, you should be able to just give them a number (a reasonable one) and they should give you that amount. I haven't dealt with progressive, so I'm not familiar with their policies, but I just got rear-ended a little over a month ago, and my bike was totalled (thank God I was able to walk away with very minor injuries) and the insurance company I dealt with was allstate. they covered the whole amount of my bike, and all my gear...they asked for receipts and I didn't have them, but told them what I paid for all my stuff and they cut me the check, and yes I was actually honest with them, although I'm sure I could have easily made out with a couple of hundred just on the gear alone. They also paid me for 'pain suffered and inconvenience.' I don't think they'll replace the bike...pretty sure they'll just pay off the loan/cut you a check.
I wish you and your brother and family the best