Repairing a 20 year old trimmer for 60% of the price of a new one? What happens when it comes back for an ignition module or rewind pulley that is probably obsolete? Those are the machines repair shops hate, you will be band-aiding it under shop warranty for the rest of the season and the customer will be pithed at the frequent trips to your shop. IMHO, it is a no win situation.

Piston Power products made the L.b. weed wacker ....I would have junked it,before repairing it for a customer ....but if it was in excellent shape you saved him $40.00 :o)
Tough call ,Jim

I forgot to mention that the $99 model was at a big box store for a piece of junk. It seems like Lawnboy put out a good product and it was worth fixing, after all, it was used for 20 years.