Uncle's capitalisation was correct - Lsd. The letters were even used at times as a colloquialism for money. "Now let's talk about the Lsd".

Five pounds, one pound and ten shillings were the values of the notes in common use while there were coins for two shillings and six pence, two shillings (sometimes called a florin - an older name for it), one shilling, six pence, three pence, one penny, a halfpenny and a farthing (quarter of a penny) which, along with the threepenny bit, disappeared before the others. The threepenny bit was thick and heavy and I assume that is why it alone was called a 'bit'.

When I was a boy, the two and sixpenny coin (known as half a crown) was given the slang description of 'half a dollar', giving some idea of the exchange rate at about that time - or rather, I suspect, just prewar.

Is that all clear?