how to record 'net tax' on a CRA assessment

New client, behind in GST remittances
they have a note from CRA which estimates what the GST amount will be, ie
   net tax 300.00
   arrears interest 28.00
   penalty 12.00

so I would pay expenses for 340.00, and
   db xxxxx 300.00
   db non-deductible penalty 12.00
   db bank/interest 28.00

would xxxxx be 2325 - the gst/hst adjustment account ?

presuming GST paid purchases is 0.00, and I record 7000.00 in sales
account 2310 (gst charged on sales) would have a 350.00 credit balance

is there a line on the GST remittance form to record the earlier 300.00 payment ?
or do I report
   line 101 7,000 sales
   line 103    50 gst collected
   line 106     0 gst paid ITC