[Heathkit] SB-610 P.E.C.s & Diode Questions

[carl lowry]

Doing some repairs ( again ) on another  SB-610 Monitor Scope
& changing also out some parts that are either leaking caps or way out of tolorances resistors.
Got looking at the Silicone Diodes - theres 4 of them in a string - crummy looking,
in the power supply section. They are identified as D1, D2, D3, & D4 right off the transformer.
They are not further identified anywhere in the manual.
I've previously changed out the 2 Selenium Rectifiers with  four Vr/1000 vdc 1N4007 Diodes.
Any problems in - if necessary also using the same with the 1N4007 Diodes for these D1 - D4 as well ?
Second question please - what are the 1500 cps P.E.C. & the 1950 cps P.E.C. - Packaged Electronic Circuits ?
If i break a leg on one of them - am i up the creek or are these still available ?
Thanks guys.
73s
Carl, k4zrd