Upvote:4
As a Canadian citizen then you don't need a visa to enter the UK as a visitor.
As you are just entering for a period of 1 week, have no intention to stay longer, then this should not represent a problem for you so long that you are able to;
The border agents want to be sure that you will leave the UK. So as long as you already have a flight booked (which is anyway normally cheaper when done well in advance), haven't previously overstayed in the UK, then they should be happy.
And if asked just be honest and say "I previously been in the UK on YMS scheme, I have been travelling around continental Europe for xx months, and I am visiting friends in the UK and collecting property that they kept for me before returning home to Canada to my family on xx date."