I just checked my front, 27 year old, Cinelli fork for damage. The bicycle was involved in a collision. Top and down tube slightly dented. I checked the axel and crown level and they are parallel. The offset (trail) I measured came to 1.732 in. Could I assume those fork were build with a 1.75 in offset and therefore would be OK?
Fork rake (offset) and trail are different things. A fork rake of 1.75" is reasonable, but trail is usually about 2" to 2.5" on a bike with a 73° head tube angle. If the dents in the top tube and down tube are bad enough to change the head tube angle, it would have an effect on trail.
Dave Moulton has a nice blog article on rake and trail HERE.