Depending on the fleeces and the ambient temperature, you may be lucky. I was asked to find homes for some Heb fleeces last year, the lady said another spinner had taken two and said the others were fine to use, but she could only use two. By the time I got to collect them, they'd spent a month in a black plastic sack in a garage and were felted to heck.
But if they've been somewhere cool and aren't a felty type of fleece, you may be lucky.
A lot of people say that if a fleece isn't washed in the first few months then it becomes unusable. This is rubbish; if it's been stored correctly it will last for years. In cooler weather the grease will harden, and be more difficult to shift. But you can still wash it out - and you can even still spin 'in the grease' if you want, you just need to get the fleece nice and warm
(It's never quite the same as a fresh fleece, though, so I would usually wash an older fleece, not try to spin it in the grease.)
I've heard of people using 19 and 20-year old fleeces, and they were still nice. (Or at least,
some of them were.
)
As FW days, take the bags out into the garden and open them up. If clouds of dead moths fall out, chuck the whole lot away
.
As you are both spinners, you don't need us to tell you how to tell if it's a usable fleece, but for the benefit of other readers who may not be spinners, test 1 is to try to pull the fleece apart; if it parts readily with no tearing sound, that's a good sign. If it's a mat, won't come apart at all, or only with tearing, then it's felted. Depending on the lock length there may still be usable fibre, you'd need to cut the felted butts off. Generally that's more work than the fleece is worth, so unless you want a felted mat (they make good seat pads, dog beds, etc.) then discard it. Do check that it's felted all over, of course - there may be some usable bits.
Test 2 is to take a lock out of the mass - pull it out by its tip, the pointy bit. Hold both ends, hold the lock next to your ear, and snap it. If it crackles or breaks, it's no use. If it makes a good pinging sound, it's strong. Check locks from a few areas of the fleece.
Test 3 is to see if the individual fibres will draft. With the lock you've just pinged, hold the butt end loosely and take a few fibres from the tip end, draw them away from the rest. There may be some initial resistance but the fibres should then glide free. If they make a tearing sound, or won't come, then it's probably not going to be a spinning fleece. (But do check that you aren't holding the butt end so tightly you aren't
allowing the fibres to be drawn out
)