fine point paint pen

[guest311]

while not specific to N guage, I am wondering if anyone can recommend some form of cheapish black fine tipped marker / paint etc pen.

I am modelling some desert scheme 20mm vehicles for a wargaming mate, and I need to be able to add arabic numerals for the callsigns.

I have found the numerals but have not been able to source them as transfers, so looking to free hand them onto the models before the final matt varnish coat.

any info / suggestions very much appreciated.