Since many forums aren't happy with posting links to other forums I've provided this link that I have written up a Step by
Step on
adding wheel wipers to two different Mantua engines. One is an 0-4-0 with tender the other is a Mantua 2-6-6-2 with added tender.
The link to the Model Railroad Hobbyist shows how I installed a Lenz decoder and added
wheel wipers changing the poor four wheel pick
up to all wheel (12 wheels) pick up.
The link to the Model Railroad Hobbyist shows the critique of the Mantua 2-6-6-2 Tank Engine.
It shows the extensive problems of the engines drive train,
namely the wheels and rods of the engine.
It also shows how I installed all wheel pickup. Plus I added an auxiliary tender that gives me 32 wheel pick up.