Dick G....
Probably not a problem.
But a ukelele will be less obtrusive than a stand-up bass.

...and borders are always a bit randomly weird these days...

(Seriously, the three concerns are...
...are these the tools of your trade/are you coming to work?
...are you trying to avoid duties/sales tax by importing them?
...do they contain bombs?

If no to all three, then no problem. But don't leave them visible, or mention them.)

_john the wise.