Für dieses Werkzeug haben sich viele Ausdrücke eingebürgert:

Il tasso è uno strumento utilizzato dai carrozzieri come incudine di precisione nella battitura delle lamiere, ed è costituito da un supporto di acciaio pieno.
Durante la lavorazione viene appoggiato alla lamiera da rifinire e dalla parte opposta si percuote con il martello idoneo, fino ad ottenere una superficie debitamente curvata. Può essere di diverse forme, a seconda delle parti da rifinire e delle curvature da riprodurre, e la superficie può essere zigrinata o piana.
https://it.wikipedia.org/wiki/Tasso_(strumento)

A dolly is the name given to a category of tools used in shaping sheet metal. In general, a dolly is a solid piece of metal, small enough to hold in one hand, with a curved or shaped face. Generally a dolly will have more than one surface, each with its own radius of curvature (much like a three-dimensional French curve), allowing the craftsman more flexibility in using the tool.
:
• Heel dolly: Has a long radius on one side and a flat on the other, hence they look like the heel of a shoe. One face is domed and that other is flat.
• Toe dolly: Has a short radius on one side and is twice as long as the heel. Similarly it has a domed and flat side also.
• Wedge dolly or "Comma": It looks just like a comma, the narrow side makes it ideal for tight contours.
• General purpose dolly or "Track": Has many different surfaces and contours, easy to hold while dealing with substantial blows.
• Egg dolly: Rounded all over in different contours but on one side it does have straight edges and angles.
https://en.wikipedia.org/wiki/Dolly_(tool)

dolly n (Auto) / Ausbeulklotz m, Ausbeulwerkzeug m| (Autos) / Anhängerstütze f
(Kučera, The Compact Dictionary of Exact Science and Technologie)

dolly (1) (mot.body.tool) (gen.) hand dolly, dolly block AE
• Handfaust, f/-fäustel, m
• Gegenhalter, m
• Handklotz
• Handeisen
• Vorhalteeisen
dolly (2) (mot.body.tool)
• ) Stöckle, n Werkstattsprache
• Gegenhalter, m
(Schmitt, Fachwörterbuch der Kfz-Technik)

dolly der Gegenhalter Pl.: die Gegenhalter
dolly der Vorhalter Pl.: die Vorhalter
https://dict.leo.org/englisch-deutsch/dolly