This piano hasn't been serviced for some years. One would assume dust bunnies gather on keybed and enclosed pedal area. Carefully exam the piano, see how parts are going to be taken off. Every piano is different. If needed, take pictures of disassembly process. Remove keys makes it easier for a thorough cleaning.
If any parts are broken, fix first. This key button was cracked. Ideally wood glue would be used. There was only super glue in the tool bag, better than nothing. Looks like someone was tuning this piano from 1973 to 1989. This piano was made in 1973 according to the serial number.
Many thanks to the customer to have family vacuum cleaner ready to use. Clean key sticks, keybed, and enclosed pedal area.
All cleaned. Put keys back and tune.
Almost to the time to collect service fee and get out. Do not rush, take care to put the piano back together. Make sure all screws and washers are tight. The left and middle pictures show places to screw down key up stop rail. The right picture shows where fallboard rod is attached to the fallboard. This structure is typical on small vertical pianos and spinets.
Piano is carefully put together now. Write down all work involved during this service and hand to the customer. Next time there will be a reference of what has been done. If they happen to call other technicians for the service, this would be helpful, too.