Re-purposing and weathering a Rails/Dapol Terrier

[whart57]

I have bought a second-hand Terrier in K&ESR livery and I want to remove the name and K&ESR markings and then weather it to be more like a 1930 condition loco. I don't want to change the Stephens house livery of blue and red lining though so a complete respray is not the intention.

 

I gather from reading through the postings here that a cotton bud and thinners should remove the tank-side lettering and I'm OK with creating transfers for my fictitious addition to the Stephens empire, including the buffer beam numbering Dapol have left off.

 

My main questions are regarding the weathering, mainly because I haven't weathered an RTR loco since following the Terence Cuneo instructions given in the Triang "First Ten Years" book on my Triang Nellie nearly sixty years ago. Since then I have only worked on things I have built - and painted - myself. Disasters can just be cleaned and repainted.

 

So basic questions first:

 

1:  Should I protect the original finish with varnish - in which case would that be acrylic or enamel?

 

2:  Weathering powders are new to me, are they recommended over paint? In which case whose powders?

 

I've been through a dozen pages or more of entries in this forum and it doesn't seem that many have written about weathering steam locos, so I hope people don't mind these Weathering 101 questions.