Fòram na Gàidhlig

I wanted to practice a little bit more to try and work on my grammar and vocabulary, so I tried to tr*nsl*t* the first paragraph of a book. Could someone please look over this and correct it where necessary?

Bha i mo là-breith nuair a ghlaodh mo aba mi anns an oifis aige agus thug dhomh a' litir sin uabhasach: Tha sibh òrdaichte a nochadh air beulaibh an Oifis Naomh 23 Iuchair anns am bhliadhna seo Ar Tighearna, 1264...

I'd say

'S ann air mo cho-là breith a dh'iarr an t-aba agam orm a thighinn dhan oifis aige agus thug e dhomh an litir uabhasach seo an uairsin: Tha sinn a' cur òrdugh oirbh nochdadh air beulaibh na h-Oifise Naoimhe 23 den Iuchair am bliadhna ar Tighearna 1264

I'd use a much more formal style in the letter itself (hence the feminine genitive Oifise Naoimhe, den and oirbh)