Feeling a little OCD so did some number fumblings for you.
Follow if you dare. First off, I was thinking who figures out volume in cubic inches, obviously only small volume thinking there. So I found a converter and cranked it into cubic feet.
http://www.metric-conversions.org/volume/cubic-inches-to-cubic-feet.htm You get 62 in³ = 0.035879 ft³. So, I then flipped that to ounces as that's what the US Power Tank guys have on their handy little chart here:
http://www.powertank.com/charts.specs. Did that via the power of a converter on my mac. From 0.035879 ft³ you get 34.354375 fluid ounces. The chart generalizes it a bit as PSI isn't directly mentioned but PSI can sort of be compared to output power in relation to volume (which is kinda dependant on CO2 being a liquid and converting to gas as it depressurizes, that's why they measure CO2 via weight, but that's getting WAY too technical for a "how many fills" question). SO, you're ALMOST at 40 oz. there which is about a 1/4 of a 5lb tank when empty. SO, using the OTHER handy chart there (keeping in mind that's the IDEAL situation there, you'll get less. If you aired your 31's from around a 30 ish PSI to around 10 you'd have a 20 PSI difference to refill. You'd get about 15 refills with a 5lb, so like 15 / 4 = not quite 4 tires.
TA-DA!! I'm S-M-R-T-R than everybody! Or so my Mom tells me.
Pretty sure the logic is fairly sound on the 1/4-ish amount thing there. If you look at the fill up chart a 5lb has 1/4th the amount of a 20 lb. But the weights ARE a little wonked... So maybe +/- it by a factor of.... 2 tires. So 1.5 to 6 individual tire fills. And I just looked up a pic of that sized tank and am going to hazard a guess towards the low end of that logic.... But, I could be way off, just fill it up, park at a 7-11 with a compressor and dump your tires. Actually do it, and let me know the results.
Any regulator you could fit on that thing will have an awful flow rate which will hack the PSI WAY down, so if it DID work, it would be slow. And you'd be draining the cylinder so fast it might just ice up solid....
Prognosis: get a bigger tank (10 lb min) and a PowerTank, Source or comparable HIGH flow pass-through or adjustable regulator. Bed time for me!