This is from a classified ad on Sports Car Market site, I would be surprised if it was not 14.5 cm tall:
from Model 41 Royale. Piston weighs 5lb, 5oz. It is 14.5mm tall, and has been cracked and repaired. Shows excellent repair. Purchased at the Stable fo Thoroughbred auction in Dec., 1965. The car brought $6.4m at the Harrah auction following his death. Also looking to get rid of 183 copies (mint condition) of Automobile Quartetly (Vol1 #1-Vol46#3). If anyone would care to make an offer it will be taken into consideration, and appreciated.