My grandfather had a different way with sloe gin - he wasn't concerned with decanting or maturity.

Autumn
Take 1 bottle of gin & 1 empty gin bottle
Divide the gin between the 2 bottles
Fill bottles with sloes, and sugar to taste

New Year's Eve
Start drinking from bottle 1

January
Continue bottle 1 until almost empty
Refill bottle 1 with gin
Start on bottle 2

February - April
Repeat as necessary

May - December
Drink elderberry or parsnip wine.

It worked for him - and I was allowed a glass at New Year (aged 9)

Phil