A combination like that is not an original state but a pen assembled from the parts of two, known among collectors as a “frankenpen”. The barrel of the 136 belongs to the Meisterstück line of the 1930s and 1940s, the cap shape of the 244 to the 1950s, so there are some fifteen to twenty years between the two parts. Such pairings usually came about because the original cap had broken or been lost and whatever fitted reasonably well was put on in its place. The barrel can be identified from its shape and imprint, the cap from its shape, cap ring and clip; proportions that do not match at the joint, and a cap that does not sit flush, are further pointers.
To a collector such a pen is worth appreciably less than one preserved in its original form, and it should always be described explicitly as a composite when sold, all the more so if the nib is damaged into the bargain. Anyone wanting to make the two pens whole again will find matching caps, barrels and nibs most readily at collectors' fairs and by swapping with other collectors. Celluloid bodies call for care: polish only very gently, and remember that the cork seal of the piston dries out in long storage. Collectors therefore keep it damp with distilled water now and then; the better long-term answer is to have the seal renewed by a specialist workshop.