IMHO:
- Never buy a "parts kit" one piece at a time, the cost will kill you.
- If a "parts kit" is missing a piece, there is a reason for it and it will cost you big $ for the missing piece
- If you are ever considering building a 1919 buy the kit NOW, the prices are only going to go up
- If you buy one now, there is a very good chance you will get your money back plus some if you do not decide to build it
That being the case, buy a complete kit (minus the RSP) from Sarco (or whoever is selling them). When you get it open it up and count and inspect every part, it anything is missing or doesn't look right have them make the kit right. Box it back up and put it on the shelf untill your ready to build.
The "don't buy it one piece at a time" thing only applies if the parts kits are still available - I think the time is coming when 'one piece at time' might be your only option.
The thing with military surplus firearms is that sooner or later - the supply of them is GONE. I've seen it happen over and over again in the few short years I have been involved in this. CMP had a warehouse full of Garands and 30.06 ammo - go check out their pages now - you're picking thru scraps compared to what was available just 2-3 years ago.
The German MG34 and MG42 machine gun kits were freely available just 2-3 years ago - now the MG34 stuff is almost gone - and going up in price. The MG42 stuff (German) is disappearing - and will shortly be gone - and even the MG53 (the Yugo stuff), is much less freely available than it was a few years ago.
You used to be able to get 1918 BAR kits - now you can pretty much only get newly built rifles from OOW - for like $4500.
From what I can see watching the prices of fully built 1919a4's on the market - if you buy a kit in the $800-1000 range - and pay somebody to build it (will probably run $5-600) - you will likely still get your money back out of it even if you turn around and sell it tomorrow. Hold onto it for a few years - and the prices will in all likelihood have gone up even more.
I agree with you on the "buy it now" thing. Buy the kit first - those will disappear first. Buy the right side plate next -once the kits dry up that market will dry up too and people will get out of the business of building sideplates - then buy the rivets and anything else you need to build it up.
I think sooner or later there will be an option to build a 1919a4 out of all new parts - but that might take a few years for all the different people making the parts to come together and make it happen. The blueprints to make the parts are available - so it would only take manufacturers who see a profit to be made to make it happen.
It might end up being an item like the 1918 BAR's though - only available from one or two sources - and costing $4500 or so - to get into one.
If you want to get a tripod for it - you've got three options that I know of:
the original M2 style (there are newly mfg ones available for cheaper than the originals)
These are available just anywhere you look for 1919a4 stuff.
one of the German MG3 style:
http://www.robertrtg.com/mg3tripod.html (still pretty cheap but these will dry up once the supply is gone)
and the Mag58 style:
http://www.gunpartscorp.com/catalog/Detail.aspx?pid=983100&filter=983100 The Mag58 tripods seem to be all over the place on price - Numrich has them at a decent price - and then other places sell them for up to $900 each.
Both the Mag58 and MG3 tripods will need some sort of adapter to mount a 1919a4 on them.