These are excellent meters, why not sell yours on, and buy one with a converter ? The AC and Ohms boards are like hen's teeth, as you are no doubt aware; there is one on Ebay, atm.
The 8800As with batts are easy to spot; there is a note on the instructions on the bottom of the meter, again, there is one on Ebay, atm. So it seems a shame to change a meter from factory spec, as they are not particularly rare.
ISTR the 8810A is TRMS, whereas the 8800A is not. AC and Ohms were factory options on the 8810A, and the 8810A is limited to 750VAC.
Mine is a later one, and looking at the date codes on the chips inside, it was made around 1980, and is spot-on, against my recently calibrated 89. The spare fuse is still in the clip inside, which is a nice touch.
If you are looking for a wel-spec'd, compact and relaible bench meter, they are an excellent buy.