>> "Increase difficulty level by one for every decade of ship age"??

> Are TU Free Traders really that rickety?

Well, how long does a ship last? IMTU a military ship will probably last
100 years (i.e. two major refits) before it gets retired from the front
line of battle. After one more refit (i.e. it's now 150 years old) it
will probably get sold off to some minor power, or demilitarized and
sold to some hapless PCs/NPCs, or something. After one or maybe two more
refits (if these even happen) the ship is probably getting pretty creaky
and unreliable, and may not be easily fixable, even in a shipyard. Of
course there is an economic aspect to this too. Major refits are
expensive, and take the ship out of commission for months at a time.

I might change the roll to "Increase difficulty level by one for every
decade since last major refit". As a GM, you probably want your player's
ship to break from time to time (or for them to encounter some NPCs
whose ship has broken in some inconvenient place). Hilarity should then
ensue :-)

Jonathan