Most USB sticks use the PC partitioning format, and have a single partition. That means the first sector (512 bytes) of the disk contains a partition table (and optionally a bootloader), and the rest of the disk contains the partition.
You could have rescued just the partition with
ddrescue -f -n /dev/sda1 /dev/sdb8 logfile
ddrescue -d -f -r3 /dev/sda1 /dev/sdb8 logfile
But now that you have the whole disk, you can get at its partition.
losetup -o 512 /dev/loop0 /dev/sdb8
mount -r /dev/loop0 /mnt
/dev/loop0 is already in use, you may have to choose another number. The command
losetup -f will return the number of a free loop device.
However, manipulating partitions on a live system is error-prone, so rather than do this, I recommend moving the data from the USB stick to an ordinary file. Either copy the whole disk, then use
losetup on the disk image (16M × 130 is calculated to be larger than the size of the USB stick):
dd bs=16M count=130 </dev/sdb8 >/var/tmp/usb-stick.disk
Or copy just the partition, and mount the partition image directly:
tail -c +513 </dev/sdb8 | dd bs=16M count=130 >/var/tmp/usb-stick.partition
mount -o loop,ro /var/tmp/usb-stick.partition /mnt
And for future reference, you might as well have passed an output file, rather than an output partition, to
ddrescue in the first place.