Bandmaster 6G7A grid stoppers

[Diverted]

I was recently given a brownface Fender Bandmaster to look at. Owner said it wasn't putting out much volume. Tracked amp's main issue down to the output transformer, half the primary was open. Interesting thing is the transformer was not original so this amp has blown at least two output transformers.
Received and installed the transformer today and recapped the power supply. All the filter caps were original and a few were bulging like crazy. I also replaced the two 10uf bias caps.
I'm starting to take a close look at the amp now and noticed that there are no grid stoppers on the 6L6s. Anyone know why they weren't put in this circuit?
Still a very long way off from powering up the amp for the first time but was just curious.

Thanks.

https://schematicheaven.net/fenderamps/bandmaster_6g7a_schem.pdf

[sluckey]

Browse through the fender schematics in the library. You'll find plenty of amps without grid stoppers on the output tube. Why? Ask Leo.   
Easy to add them directly to the sockets if you wish.