Prospectus search

Why do they make it so difficult to find the applicable prospectus and/or prospectus supplement? In this case, there’s very likely a base prospectus with a supplement for this particular issuance. Even so, there doesn’t appear to be an easy way to search for them. Any ideas?

For example - 3130AYZJ8 (Federal Home Loan Bond maturing on 02/23/2044)

I’m trying to figure out exactly what backs these bonds. Is it just the general corporation issuing it (Freddie Mac?) or is backed by some group of mortgages (doesn’t seem so, but can’t tell unless I see the prospectus)? And obviously not backed by FF&C of USA, but maybe defacto so? In the end, I’m trying to figure out if these are the kinds of bonds that will be mostly repaid quickly as interest rates come down or not. If they were mortgage-backed, then when mortgage rates drop from 6.X% to 5.X%, the vast majority of them will be refinanced, and most of the money would be returned. That means that in essence, the holder gets 6.25% for a short period of time on most of the money, and then 6.25% on the remainder for a longer period. This is good considering that short-term rates are only 4.5-5% right now (1-2 year treasuries). 6.25% for a year or two would be fine for a portion of the fixed income allocation.