JTM45/100 build questions...

[Notthedocter]

Hi All..First off...thank you to all the members who have contributed so much to the Forum...I have learned a TON!

I am starting a JTM4/100 build. It is my first build, and have a few questions(ok a ton of questions, but will limit it to 2 at this point)..
1. I am using Belton octal micalex sockets for the power tubes. They have 2 holes on the lugs. Can I use both holes when running the heater wiring. If so, is there any advantage/disadvantage of running the wires this way? I checked out the Metroamp 100w instructions, and it looks like that is what they are showing. I just wanted to be 100% before I got going. (I am kinda expecting the "thats what they are for" but I cant take it.

Also, the PT that was supposedly recommended was the Mercury Magnetics P100JM-MMF. I cant even find this on there site. It has dual primaries, I dont think I have seen this used on any other 45/100 builds, at least to limited knowledge. I was pretty much trusting the person I was buying it through. But I came across an article that with this type of PT I would need to use a full wave grounded center tap rectifier circuit, not the full wave bridge voltage doubler like on most Marshall 100w. I really have no idea what either is. But it sounded like it made no sense to use this for a 45/100 build..any thoughts?
The wiring for the transformers are
PRIMARY:
0V=Brown 120V=Brn/Wht 0V=Black 100V=Blk/Wht 120V=White
SECONDARIES:
350V=Red 0V=Red/Wht 350V=Red
Green/ Grn/Yel/ Green = 6.3V @ 6A Filament
Yellow/ Yellow= 5V @ 4A Rectifier
Any thoughts/help on the above are appreciated...
Thank you