If Parts Are Available . . .
The PRO-2004 used older thru-hole components (axial lead parts, etc), many of which are likely not available any longer. I worked many years ago for General Dynamics as an electronics tech building the SINCGARS radio for the US Army. We were in the process of switching to SMT parts (Surface Mount Technology) from the older, larger thru-hole style components. At that time the switch was being made to start eliminating thru-hole parts so we could begin utilizing smaller SMT configurations. Since that was a long time ago I would assume by now most, if not all, of those parts are no longer available in thru-hole configuration.
I think the issue will always be if the part(s) required are still available for your PRO-2004. If so, I would assume they'll do it. If not, I know a lot of guys around the country that still work on these older technology boards and even have parts in stock from way back when (although I'm sure over time these older parts will likely be somewhat out of tolerance from when they were manufactured).
Randy