Gearbox help please - DT replacement options

[happy...camper]

Hello I have a broken DT gearbox (One of the selector fork Ball-Sleeves has broken it's outer casing and allowed the small ball bearings to escape into the gearbox - 3 ball bearings, and 2 broken bits of metal in addition to bits of the sleeve found so far) so am hoping to buy a second hand replacement to get my van back on the road. What I would like a hand with if I can borrow anyone's brain is what other codes would be a suitable fit ratio wise?

Identification codes:
DT 16 12 2
091 301 103D
251 399 205 C

4 speed
manual
petrol
24 splines
4.57 final drive ratio
diesel bellhousing i've been told

If anyone could help that would be great, I have studied the tables that list everything but its really confused me. Also is using a diesel box as opposed to a petrol box possible?

Thanks

[happy...camper]

Hello I have a broken DT gearbox (One of the selector fork Ball-Sleeves has broken it's outer casing and allowed the small ball bearings to escape into the gearbox - 3 ball bearings, and 2 broken bits of metal in addition to bits of the sleeve found so far) so am hoping to buy a second hand replacement to get my van back on the road. What I would like a hand with if I can borrow anyone's brain is what other codes would be a suitable fit ratio wise?

Identification codes:
DT 16 12 2
091 301 103D
251 399 205 C

4 speed
manual
petrol
24 splines
4.57 final drive ratio
diesel bellhousing i've been told
late transmission

If anyone could help that would be great, I have studied the tables that list everything but its really confused me. Also is using a diesel box as opposed to a petrol box possible?

Thanks

update with more info:

I'll try to keep this short but so it makes vague sense to you. My van ruby's gearbox stopped working last summer and had to get recovered home and the local garage offered to fix here till the guys gearbox guy said he won't touch t25 gearboxes so I've been trying to get her sorted ever since but life got in the way as it does and has kicked me in the nuts of late so I have had a push to get her back on the road as I need to use her which has brought me to point I'm at now staying with my friend in his spare van in Wales while he helps me with the gearbox which the local garage dropped for me and I brought down in my car. So with help off various facebook groups and this forum etc we found info and basically have discovered that "One of the selector fork Ball-Sleeves has broken it's outer casing and allowed the small ball bearings to escape into your gearbox" and subsequently have found bits of the casing and 3 ball bearings and one snapped part of locking key from synchro hub and broken piece of 3/4 synchro hub. The manual my friend had found turned out to be for an early box which is wildly different and my van specific manual doesn't really have any info and I don't own a copy of bently. So as i'm wanting to take up as little more time, energy and space off my friend as possible i'm thinking a known good replacement box would be best option to get ruby back on the road and I may have to switch the bellhousing and input shaft from my DT box which apparently has a diesel bellhousing on onto the replacement (I have potentially found a DK which i've now been told has wrong gear linkage attachment which is a great shame as final drive ratio is right and and unidentified box but out of 1.9l petrol, watercooled, y reg that looks right from the only side i've seen a picture of).

Questions i'm currently trying to work out/ confirm?
do you know the torque settings for the bolts attaching the bellhousing to the gearbox please?
What is the correct way of removing the input shaft?
How would a DK replace a DT (I fear linkage connection is wrong but final drive ratio right)?
Chances of an unknown code box out of a 1.9l watercooled petrol y reg panel van fitting? (seen photo from side not with gear linkage and looks alike)
Would a diesel box work?

I would really appreciate your help

from the tables ratio wise it tells me I need a 4D, ABB, DK, DP or DT to match (but don;t know if all these physically match to be dropped in in place) or a similar ratio of a 5D, ABD, ABE, ACW, AOJ or DU (again same doubt as above). So also if anyone could confirm which of these would be goers and even better if you have a working one you're looking to sell

[multisi]

The DK box is shorter than the later gearbox so a spacer bracket would be needed aswell as grafting the last section of the early gear linkage onto your linkage set up. The gearbox from the 1.9 water cooled maybe ABD code or similar ratio which would mean a higher revs gearbox compared to the DK, but would be easier to fit. The Haynes manual says how to remove the input shaft at the start of the gearbox chapter. 4 speed diesel gearboxes have unsuitable ratios for petrol engines.

[happy...camper]

The DK box is shorter than the later gearbox so a spacer bracket would be needed aswell as grafting the last section of the early gear linkage onto your linkage set up. The gearbox from the 1.9 water cooled maybe ABD code or similar ratio which would mean a higher revs gearbox compared to the DK, but would be easier to fit. The Haynes manual says how to remove the input shaft at the start of the gearbox chapter. 4 speed diesel gearboxes have unsuitable ratios for petrol engines.

thankyou