DOM 1907 , Take Down in .22lr . 

She cycles , fires & ejects really fine just
doesn't cock on close consistently .

Requires the trigger to be lightly clicked
forward which will set the hammer.

It is in VG to Fine cond. and hasn't been 
opened up.

Not going to be a daily shooter but a nice collector.

Would you / should I chance hzaving some
one repair her ?
....skwerl

Vall's suggestions are very good possibilities. Another is a sticky fly in the hammer. All kinds of crap get into Winchester via the open air design, not to mention gummed up lube. Take it apart and clean out the entire thing, adding fresh lube sparingly before you send it for repair or buy parts that may not be needed. One way or another you have hold of my favorite rifle- enjoy it

The OP stated that he had to push the trigger forward until it clicks in order to cock the hammer. Sounds like a set trigger to me. I have had this happen but not coupled with the hammer failing to stay at full cock when the lever is activated.  Setting the trigger lowers the knockoff a bit allowing the sear to pivot into position to catch the full cock notch. There is a rare factory variation with 2 flys that purposely lets the hammer fully drop.  My first high wall has this type of hammer. 
Some additional info from the OP is needed 

Jack