the roman numerals are essential - translate them into arabic (ie usual notation) by all means (in fact probably better for ease of reading - remember ob = 1/2 q = 1/4 obq = 3/4 watch the x's and v's and the last '1' eg in viij (8) should always be a j (count the dots is easier) but you need the rents which until c.1780 are always given in Roman to positively identify the holding - it is worthwhile first transcribing a lib assed (eg for your time period 1726 and possibly 1740 to close) - this gives you the holdings which are then altered by lib vast - you can then work through the changes on say a single treen and check you land up with the same tenants