A couple interesting Towers Handcuffs

This Towers Handcuff barely caught my attention; there have been so many keyless Towers passing through recently that I don't mind missing a couple. 

However, it turns out this is a Towers single lock bottom key Handcuff. This is significantly more interesting and much more rare. It's too bad there's not a key. $199.99 or best offer. 

Above, detail of the key hole. 

Below, a very good condition Towers Double Lock Handcuffs with an interesting stamp reading "740" or possibly "3740", the 3 is very faint. 

There is no key to these, which is quite possibly part of the background story on these cuffs; one shackle has been cut, and thus will no longer engage into the lock body. It would seem that someone got stuck in these without a key at some point. Maybe the lock failed closed?  These are 60 CAD, ($44) or best offer. 

Above, detail of the stamping.