Good Evening Frontal,
I'm a bit late posting.
Nice soil. Very nice OM values.
Recommended desired Phosphorous values as measured by Bray P1 (weak Bray) should fall between 22 and 33 ppm.
For every 1# of P2O5 (P2O5 is the form of phosphorous that will be found in any fertilizer containing Phosphorous) that you add per one thousand sq feet of soil, your Bray P1 test should show and increase of 9.5 ppm. e.g. Adding two pounds of P2O5 to your back yard which has a current P level of 18 ppm will increase total P to 37 ppm. (In the ideal world, of course
Potassium levels that fall below 40 ppm, have been shown to result in poorly performing turf. To achieve recommended sufficient Potassium levels test levels should exceed 110 ppm (as measured by Mehlich 3, which is the recommended major cation extractant for the North Central Region per NCR No. 221 that Great Lakes states that they employ). The "optimum" range for Potassium can fall between 110 and 180-200 ppm. For every pound of K2O (K2O being the form of potassium found in fertilizers) that you add to 1000 sq feet of soil, your test values for K should raise by 18 ppm.
As Becky mentioned, your pH values should create no impediment to healthy, attractive turf. I personally like to keep mine just south of 6.5 for balanced micronutrient availability and enhancing the microbral environment. (Admittedly, + or -.04 probably doesn't make much difference to either). However, although studies don't show much impact on plant health and performance, Ca:Mg ratios do appear to have an influence of soil tilth/texture. The ideal ratio falls between 7-10:1 (depending on who you believe). Your soils Ca:Mg ratio is less than 5:1, so I agree with your desire to increase your calcium and Ca:Mg ratio. If you're going to add calcium, you might as well do that via lime and address pH adjustment. Keep in mind that adjusting one major cation (Ca) will most assuredly effect the others as a % of base (Mg, K and Na). You will not want to allow Mg levels to fall below 140 ppm sufficiency levels and certainly not below 50ppm levels that can adversely affect turf health and quality.
Hope that is at least some small help in your decision process.