It's not clear from your post if you used the built-in FileMaker Recover command on the crashed file first. If not, take an untouched (by other tools) copy of the FM file and use the built in FM command from the FMPro app.
If you tried that and it failed, check with some of the FM-developer outfits which do file fixes. I would not expect a non-FM-specific utility to recover/fix any FM file.
Absolutely used FM's recovery tool first and ended up with the file with only 1 of 20 or so tables recovered. I'm in love with FileMaker except when it does this to me...
So it's time to move on to other FM-specific services:
Check with some of the FM-developer outfits which do file fixes. I would not expect a non-FM-specific utility to recover/fix any FM file.
Most of these are listed on FMI's website under Consultants > Platinum members. FileMaker Inc also does tech support for files, but am not clear as to their current limitations and conditions on Recovery services. See:
And, while it may not your first priority at this instant, don't overlook the training/behavior-modification potential for teaching your client to do backups from now on.