Short answers, pulled from the story.
A total of $50.1 billion worth of supplies was shipped under the Lend-Lease Act between 1941 and 1945. This amount represented 17% of the total war expenditures of the U.S.
Specifically, $31.4 billion went to the United Kingdom as part of the distribution of funds during the program. The distribution of loans included 90% allocated to the UK.
Lend-Lease ended on the 2nd of September 1945 following the surrender of Japan. Large quantities of undelivered goods were in Britain or in transit when this date arrived.
The final payment of $83.3 million (£42.5 million) was made by Britain on the 29th of December 2006. This payment concluded the obligation due on the 31st of December 2006.
In total, 92.7% of the wartime procurement of railroad equipment by the USSR came from Lend-Lease. This included 1,911 locomotives and 11,225 railcars shipped to support their war effort.