Is it time to think about engine work?

[WarpathEngineering]

I've been asking multiple questions on the forum about different issues I've been dealing with on my 78 and I thank all those who have responded. This question may be short sighted or even a severe reaction to mild events but I'd like to have your comments in either case.

First a little background - I bought this truck out of state back in December and have been tinkering with it ever since and while I've enjoyed working on it as time, money and the weather will allow, I don't want to get into this thing so deep that I'm throwing my money away. Being a person who likes to do things right the first time, is intimately familiar with Murphy's Law, and is guided by the snowball theory of maintenance, here is a list of repairs already done on the truck:

Rebuilt carb - old one was misbehaving ---v
New vacuum lines - cracked, split & wanted to unburden the engine of all the emission crap --v
Headers - had to remove the manifolds to get some of the emission crap off & they warped --v
Repaired 2 exhaust manifold bolt holes - hey this things old --v
Plugs, wires, cap, rotor, coil, air filter, oil change, pcv valve - might as well while your in there --v
Valve cover gaskets - would have leaked when I mounted the plug wire looms to the bolts --v
Alternator - loose post connection --v
Battery - 6 yrs old & weak --v
Starter - intermittent at best --v
Belts - why not everything else is new --v
Thermostat & housing - housing was leaking & corroded and if your gonna do that..... --v
Fuel pump, lines & filter - was leaking

Now that I've got it running again (it's got less than 20 miles drive time since I've owned it) it looks like the oil pan gasket (cork) is leaking and possibly the front and rear main seals are as well. That coupled with the possibility that the cam lobe for the fuel pump may be worn down to the nub (see post Next question - fuel filter not filling) I'm wondering if it's not time to just jerk the engine & either run thru it, swap it with a crate motor or continue with this a la carte renewal? Some things to consider - The truck shows 40K on the odometer which given it's age is more like 140K. With that in mind, the valve train and top of the heads looked brand new when I removed the valve covers, no gunk build up what so ever. I have not run a compression test on it but it doesn't drive bad, what little I've driven.

So after a long winded intro, I'd like to hear from you. If this was your truck and you didn't need it as a daily driver and could work on it (outside when the weather cooperates) at your leisure but didn't want to break the bank either, what route would you take from here?