Case W7E info please

Hi Folks, I picked up an old Case W7E loader with cab, bucket and forks for compost work on my farm. It's actually in fairly decent shape, considering it's age. It's the newer W7E, where the body panels are more square, unlike the older, more rounded ones. The fellow who owned it (a Farmer/Mechanic) was using it to move round bales and even did some snow clearing with it for the County. But, he's moved onto a newer machine, and this W7E is now in my pole shed. I'm trying to figure out a few things about it. First, the date of the unit. the Serial number is 9900121. I can't seem to find what date that translates to. I was surprised to see that Case hardly acknowledges they ever made this model. Anyway, I'd also like to know which of the several W7E parts manuals would be the right one for this? And while we're on parts, there's a parts unit available from the same fellow. He got it shortly after he purchased the W7E. In 8 years, he only robbed a driveshaft from it. The parts machine looks kind of sad, but seems to be all there. However, the parts machine is a bit older, with the rounded body style. Unfortunately, the parts machine serial plate is missing. I can't even confirm that the parts machine is a W7E, as it was repainted covering stuff up, and I don't know anywhere enough about these to look at it and tell which of the W7's it is. This is really reaching for some info that just might no longer be out there, but does anyone know if much from the older style will fit the newer style? I'm trying to determine if it's worth it to me to go through the hassle and expense of getting the parts machine. I know this is just junk to most, and with the capabilities of the newer stuff, I understand. But, for me, this will be a leap forward in handling several thousand yards of compost, and a bonus of having forks on something besides an inside forklift. I appreciate any and all help, hints, bits of info anyone would be kind enough to pass along.