You’re really asking this question?
Your bike was nicked, they paid out within 3wks, and you’re thinking about stiffing them by ‘stealing’ your old bike?
Unless they royaly screwed you over on the price they paid out you’re building up a whole bunch of negative karma (and breaking the law).
No wonder bike insurance costs are increasing (on behalf of everyone else, thanks by the way…)
Call them up, they won’t want it back so will take much less than the actual value, you get your old bike back, a new bike, and you aren’t screwing the rest of us with higher policies.
Job done.