You can do one of two things. 

1.  Stick 1.0K to 2.2K 5 watt resistor where the choke used to be and call it good.  The resistor values really effect the preamp voltages and how much "sag" they see as much as anything else.  Of course they do drop the screen voltage, as well.

2.  Put a 50 watt Marshall choke in there.  I use the Mercury Magnetics and you can't get them from Plexi Palace (www.vintageamps.com, I think).  You could also use a Bassman 5F6A choke.  I much prefer these amps the choke installed if your looking for Plexi sounds.

Either way install a pair of screen resistors on the output tubers.  1.5K @ 5 Watt ceramic.  I put them right on the tube socket between pins 4 and 6 for 6L6/EL34 amps.

Regards,
Doug

A person can never have too many guitars or fishing rods.
Have Fun & Be Happy!

dwoodall@iname.com
-------------------
Traynor was one of the first tube amp designs in the sixties to let go of
the choke ... Traynor used a 470ohm/10watt resistor in lieu of a choke,
Marshall started doing the same thing only in their JCM900 amps ... if you
A/B any tube amp with a choke or not you'll likely find it very hard to
notice any difference - if someone here has an amp that is senstive to
choke inductance I'd like to hear about it ...

cheers, jc

Group-
  After months of troubleshooting, and asking for advice. I finally
figured out what was wrong with my old Traynor YBA-1.
I bought all new caps, I bought a new OT,I downloaded any schematic I
could find. I A/Bed it against another model with a slightly different
circuit. I spent many nights scratching my head, I couldn't figure it out.
Then preamp tubes were not showing any voltage but the power tubes were.
And for some reason the Large 450v cap that
the preamps ran to, wasn't showing any voltage either. I decided this
morning to jump the CHOKE.......well you guessed it,yep it was the DAMN
CHOKE. It sounded good with out it and there is no loud humming. Although
I did get a little excited and blew a cheapy speaker that it was connected
to. That brings me to this question if the speaker blows, does the OT
still have a load on it?
I just wanted to say thanks to the group members that gave me some good
tips. I feel so good that I fixed this amp, and I was damned if I was
going to send it out...it wasn't so much about money but having the
satisfaction that I fixed it myself. I had no idea what I was up against
when I first got it. The guy told me it had a bad OT. That was it. Even
though a more experience tech may have figured it out quicker, I consider
it a milestone. Damn the circuit wasn't even wired right when I bought
it., Anyone need a tube amp fixed....I can't tell you how long or how much
it will take.....but it will be fixed sometime! Now its just a cosmetic
thing. I want to replace some components and possibly put a new choke back
in it.

John
Pittsburgh
-------------------
The 7027 is just another 6L6GC variant, albiet a much heavier duty one.