Darn flex driveshaft broke on my trimmer. Was trying to figure out the part number for it and came up with 4137-711-3202 for the flex and 4137-711-3200 if I go with a solid one. I also came up with 4137-711-3203, but not sure how accurate that one is. Could anyone comment if any of those might work and what would be a good price? Many thanks.